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1 #
2 # (C) Copyright 2000 - 2008
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 U-Boot uses a 3 level version number containing a version, a
130 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
131 sub-version "34", and patchlevel "4".
132
133 The patchlevel is used to indicate certain stages of development
134 between released versions, i. e. officially released versions of
135 U-Boot will always have a patchlevel of "0".
136
137
138 Directory Hierarchy:
139 ====================
140
141 - board Board dependent files
142 - common Misc architecture independent functions
143 - cpu CPU specific files
144 - 74xx_7xx Files specific to Freescale MPC74xx and 7xx CPUs
145 - arm720t Files specific to ARM 720 CPUs
146 - arm920t Files specific to ARM 920 CPUs
147 - at91rm9200 Files specific to Atmel AT91RM9200 CPU
148 - imx Files specific to Freescale MC9328 i.MX CPUs
149 - s3c24x0 Files specific to Samsung S3C24X0 CPUs
150 - arm925t Files specific to ARM 925 CPUs
151 - arm926ejs Files specific to ARM 926 CPUs
152 - arm1136 Files specific to ARM 1136 CPUs
153 - at32ap Files specific to Atmel AVR32 AP CPUs
154 - blackfin Files specific to Analog Devices Blackfin CPUs
155 - i386 Files specific to i386 CPUs
156 - ixp Files specific to Intel XScale IXP CPUs
157 - leon2 Files specific to Gaisler LEON2 SPARC CPU
158 - leon3 Files specific to Gaisler LEON3 SPARC CPU
159 - mcf52x2 Files specific to Freescale ColdFire MCF52x2 CPUs
160 - mcf5227x Files specific to Freescale ColdFire MCF5227x CPUs
161 - mcf532x Files specific to Freescale ColdFire MCF5329 CPUs
162 - mcf5445x Files specific to Freescale ColdFire MCF5445x CPUs
163 - mcf547x_8x Files specific to Freescale ColdFire MCF547x_8x CPUs
164 - mips Files specific to MIPS CPUs
165 - mpc5xx Files specific to Freescale MPC5xx CPUs
166 - mpc5xxx Files specific to Freescale MPC5xxx CPUs
167 - mpc8xx Files specific to Freescale MPC8xx CPUs
168 - mpc8220 Files specific to Freescale MPC8220 CPUs
169 - mpc824x Files specific to Freescale MPC824x CPUs
170 - mpc8260 Files specific to Freescale MPC8260 CPUs
171 - mpc85xx Files specific to Freescale MPC85xx CPUs
172 - nios Files specific to Altera NIOS CPUs
173 - nios2 Files specific to Altera Nios-II CPUs
174 - ppc4xx Files specific to AMCC PowerPC 4xx CPUs
175 - pxa Files specific to Intel XScale PXA CPUs
176 - s3c44b0 Files specific to Samsung S3C44B0 CPUs
177 - sa1100 Files specific to Intel StrongARM SA1100 CPUs
178 - disk Code for disk drive partition handling
179 - doc Documentation (don't expect too much)
180 - drivers Commonly used device drivers
181 - dtt Digital Thermometer and Thermostat drivers
182 - examples Example code for standalone applications, etc.
183 - include Header Files
184 - lib_arm Files generic to ARM architecture
185 - lib_avr32 Files generic to AVR32 architecture
186 - lib_blackfin Files generic to Blackfin architecture
187 - lib_generic Files generic to all architectures
188 - lib_i386 Files generic to i386 architecture
189 - lib_m68k Files generic to m68k architecture
190 - lib_mips Files generic to MIPS architecture
191 - lib_nios Files generic to NIOS architecture
192 - lib_ppc Files generic to PowerPC architecture
193 - lib_sparc Files generic to SPARC architecture
194 - libfdt Library files to support flattened device trees
195 - net Networking code
196 - post Power On Self Test
197 - rtc Real Time Clock drivers
198 - tools Tools to build S-Record or U-Boot images, etc.
199
200 Software Configuration:
201 =======================
202
203 Configuration is usually done using C preprocessor defines; the
204 rationale behind that is to avoid dead code whenever possible.
205
206 There are two classes of configuration variables:
207
208 * Configuration _OPTIONS_:
209 These are selectable by the user and have names beginning with
210 "CONFIG_".
211
212 * Configuration _SETTINGS_:
213 These depend on the hardware etc. and should not be meddled with if
214 you don't know what you're doing; they have names beginning with
215 "CONFIG_SYS_".
216
217 Later we will add a configuration tool - probably similar to or even
218 identical to what's used for the Linux kernel. Right now, we have to
219 do the configuration by hand, which means creating some symbolic
220 links and editing some configuration files. We use the TQM8xxL boards
221 as an example here.
222
223
224 Selection of Processor Architecture and Board Type:
225 ---------------------------------------------------
226
227 For all supported boards there are ready-to-use default
228 configurations available; just type "make <board_name>_config".
229
230 Example: For a TQM823L module type:
231
232 cd u-boot
233 make TQM823L_config
234
235 For the Cogent platform, you need to specify the CPU type as well;
236 e.g. "make cogent_mpc8xx_config". And also configure the cogent
237 directory according to the instructions in cogent/README.
238
239
240 Configuration Options:
241 ----------------------
242
243 Configuration depends on the combination of board and CPU type; all
244 such information is kept in a configuration file
245 "include/configs/<board_name>.h".
246
247 Example: For a TQM823L module, all configuration settings are in
248 "include/configs/TQM823L.h".
249
250
251 Many of the options are named exactly as the corresponding Linux
252 kernel configuration options. The intention is to make it easier to
253 build a config tool - later.
254
255
256 The following options need to be configured:
257
258 - CPU Type: Define exactly one, e.g. CONFIG_MPC85XX.
259
260 - Board Type: Define exactly one, e.g. CONFIG_MPC8540ADS.
261
262 - CPU Daughterboard Type: (if CONFIG_ATSTK1000 is defined)
263 Define exactly one, e.g. CONFIG_ATSTK1002
264
265 - CPU Module Type: (if CONFIG_COGENT is defined)
266 Define exactly one of
267 CONFIG_CMA286_60_OLD
268 --- FIXME --- not tested yet:
269 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
270 CONFIG_CMA287_23, CONFIG_CMA287_50
271
272 - Motherboard Type: (if CONFIG_COGENT is defined)
273 Define exactly one of
274 CONFIG_CMA101, CONFIG_CMA102
275
276 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
277 Define one or more of
278 CONFIG_CMA302
279
280 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
281 Define one or more of
282 CONFIG_LCD_HEARTBEAT - update a character position on
283 the LCD display every second with
284 a "rotator" |\-/|\-/
285
286 - Board flavour: (if CONFIG_MPC8260ADS is defined)
287 CONFIG_ADSTYPE
288 Possible values are:
289 CONFIG_SYS_8260ADS - original MPC8260ADS
290 CONFIG_SYS_8266ADS - MPC8266ADS
291 CONFIG_SYS_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
292 CONFIG_SYS_8272ADS - MPC8272ADS
293
294 - MPC824X Family Member (if CONFIG_MPC824X is defined)
295 Define exactly one of
296 CONFIG_MPC8240, CONFIG_MPC8245
297
298 - 8xx CPU Options: (if using an MPC8xx CPU)
299 CONFIG_8xx_GCLK_FREQ - deprecated: CPU clock if
300 get_gclk_freq() cannot work
301 e.g. if there is no 32KHz
302 reference PIT/RTC clock
303 CONFIG_8xx_OSCLK - PLL input clock (either EXTCLK
304 or XTAL/EXTAL)
305
306 - 859/866/885 CPU options: (if using a MPC859 or MPC866 or MPC885 CPU):
307 CONFIG_SYS_8xx_CPUCLK_MIN
308 CONFIG_SYS_8xx_CPUCLK_MAX
309 CONFIG_8xx_CPUCLK_DEFAULT
310 See doc/README.MPC866
311
312 CONFIG_SYS_MEASURE_CPUCLK
313
314 Define this to measure the actual CPU clock instead
315 of relying on the correctness of the configured
316 values. Mostly useful for board bringup to make sure
317 the PLL is locked at the intended frequency. Note
318 that this requires a (stable) reference clock (32 kHz
319 RTC clock or CONFIG_SYS_8XX_XIN)
320
321 CONFIG_SYS_DELAYED_ICACHE
322
323 Define this option if you want to enable the
324 ICache only when Code runs from RAM.
325
326 - Intel Monahans options:
327 CONFIG_SYS_MONAHANS_RUN_MODE_OSC_RATIO
328
329 Defines the Monahans run mode to oscillator
330 ratio. Valid values are 8, 16, 24, 31. The core
331 frequency is this value multiplied by 13 MHz.
332
333 CONFIG_SYS_MONAHANS_TURBO_RUN_MODE_RATIO
334
335 Defines the Monahans turbo mode to oscillator
336 ratio. Valid values are 1 (default if undefined) and
337 2. The core frequency as calculated above is multiplied
338 by this value.
339
340 - Linux Kernel Interface:
341 CONFIG_CLOCKS_IN_MHZ
342
343 U-Boot stores all clock information in Hz
344 internally. For binary compatibility with older Linux
345 kernels (which expect the clocks passed in the
346 bd_info data to be in MHz) the environment variable
347 "clocks_in_mhz" can be defined so that U-Boot
348 converts clock data to MHZ before passing it to the
349 Linux kernel.
350 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
351 "clocks_in_mhz=1" is automatically included in the
352 default environment.
353
354 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
355
356 When transferring memsize parameter to linux, some versions
357 expect it to be in bytes, others in MB.
358 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
359
360 CONFIG_OF_LIBFDT
361
362 New kernel versions are expecting firmware settings to be
363 passed using flattened device trees (based on open firmware
364 concepts).
365
366 CONFIG_OF_LIBFDT
367 * New libfdt-based support
368 * Adds the "fdt" command
369 * The bootm command automatically updates the fdt
370
371 OF_CPU - The proper name of the cpus node (only required for
372 MPC512X and MPC5xxx based boards).
373 OF_SOC - The proper name of the soc node (only required for
374 MPC512X and MPC5xxx based boards).
375 OF_TBCLK - The timebase frequency.
376 OF_STDOUT_PATH - The path to the console device
377
378 boards with QUICC Engines require OF_QE to set UCC MAC
379 addresses
380
381 CONFIG_OF_BOARD_SETUP
382
383 Board code has addition modification that it wants to make
384 to the flat device tree before handing it off to the kernel
385
386 CONFIG_OF_BOOT_CPU
387
388 This define fills in the correct boot CPU in the boot
389 param header, the default value is zero if undefined.
390
391 CONFIG_OF_IDE_FIXUP
392
393 U-Boot can detect if an IDE device is present or not.
394 If not, and this new config option is activated, U-Boot
395 removes the ATA node from the DTS before booting Linux,
396 so the Linux IDE driver does not probe the device and
397 crash. This is needed for buggy hardware (uc101) where
398 no pull down resistor is connected to the signal IDE5V_DD7.
399
400 - vxWorks boot parameters:
401
402 bootvx constructs a valid bootline using the following
403 environments variables: bootfile, ipaddr, serverip, hostname.
404 It loads the vxWorks image pointed bootfile.
405
406 CONFIG_SYS_VXWORKS_BOOT_DEVICE - The vxworks device name
407 CONFIG_SYS_VXWORKS_MAC_PTR - Ethernet 6 byte MA -address
408 CONFIG_SYS_VXWORKS_SERVERNAME - Name of the server
409 CONFIG_SYS_VXWORKS_BOOT_ADDR - Address of boot parameters
410
411 CONFIG_SYS_VXWORKS_ADD_PARAMS
412
413 Add it at the end of the bootline. E.g "u=username pw=secret"
414
415 Note: If a "bootargs" environment is defined, it will overwride
416 the defaults discussed just above.
417
418 - Serial Ports:
419 CONFIG_PL010_SERIAL
420
421 Define this if you want support for Amba PrimeCell PL010 UARTs.
422
423 CONFIG_PL011_SERIAL
424
425 Define this if you want support for Amba PrimeCell PL011 UARTs.
426
427 CONFIG_PL011_CLOCK
428
429 If you have Amba PrimeCell PL011 UARTs, set this variable to
430 the clock speed of the UARTs.
431
432 CONFIG_PL01x_PORTS
433
434 If you have Amba PrimeCell PL010 or PL011 UARTs on your board,
435 define this to a list of base addresses for each (supported)
436 port. See e.g. include/configs/versatile.h
437
438
439 - Console Interface:
440 Depending on board, define exactly one serial port
441 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
442 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
443 console by defining CONFIG_8xx_CONS_NONE
444
445 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
446 port routines must be defined elsewhere
447 (i.e. serial_init(), serial_getc(), ...)
448
449 CONFIG_CFB_CONSOLE
450 Enables console device for a color framebuffer. Needs following
451 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
452 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
453 (default big endian)
454 VIDEO_HW_RECTFILL graphic chip supports
455 rectangle fill
456 (cf. smiLynxEM)
457 VIDEO_HW_BITBLT graphic chip supports
458 bit-blit (cf. smiLynxEM)
459 VIDEO_VISIBLE_COLS visible pixel columns
460 (cols=pitch)
461 VIDEO_VISIBLE_ROWS visible pixel rows
462 VIDEO_PIXEL_SIZE bytes per pixel
463 VIDEO_DATA_FORMAT graphic data format
464 (0-5, cf. cfb_console.c)
465 VIDEO_FB_ADRS framebuffer address
466 VIDEO_KBD_INIT_FCT keyboard int fct
467 (i.e. i8042_kbd_init())
468 VIDEO_TSTC_FCT test char fct
469 (i.e. i8042_tstc)
470 VIDEO_GETC_FCT get char fct
471 (i.e. i8042_getc)
472 CONFIG_CONSOLE_CURSOR cursor drawing on/off
473 (requires blink timer
474 cf. i8042.c)
475 CONFIG_SYS_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
476 CONFIG_CONSOLE_TIME display time/date info in
477 upper right corner
478 (requires CONFIG_CMD_DATE)
479 CONFIG_VIDEO_LOGO display Linux logo in
480 upper left corner
481 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
482 linux_logo.h for logo.
483 Requires CONFIG_VIDEO_LOGO
484 CONFIG_CONSOLE_EXTRA_INFO
485 additional board info beside
486 the logo
487
488 When CONFIG_CFB_CONSOLE is defined, video console is
489 default i/o. Serial console can be forced with
490 environment 'console=serial'.
491
492 When CONFIG_SILENT_CONSOLE is defined, all console
493 messages (by U-Boot and Linux!) can be silenced with
494 the "silent" environment variable. See
495 doc/README.silent for more information.
496
497 - Console Baudrate:
498 CONFIG_BAUDRATE - in bps
499 Select one of the baudrates listed in
500 CONFIG_SYS_BAUDRATE_TABLE, see below.
501 CONFIG_SYS_BRGCLK_PRESCALE, baudrate prescale
502
503 - Console Rx buffer length
504 With CONFIG_SYS_SMC_RXBUFLEN it is possible to define
505 the maximum receive buffer length for the SMC.
506 This option is actual only for 82xx and 8xx possible.
507 If using CONFIG_SYS_SMC_RXBUFLEN also CONFIG_SYS_MAXIDLE
508 must be defined, to setup the maximum idle timeout for
509 the SMC.
510
511 - Interrupt driven serial port input:
512 CONFIG_SERIAL_SOFTWARE_FIFO
513
514 PPC405GP only.
515 Use an interrupt handler for receiving data on the
516 serial port. It also enables using hardware handshake
517 (RTS/CTS) and UART's built-in FIFO. Set the number of
518 bytes the interrupt driven input buffer should have.
519
520 Leave undefined to disable this feature, including
521 disable the buffer and hardware handshake.
522
523 - Console UART Number:
524 CONFIG_UART1_CONSOLE
525
526 AMCC PPC4xx only.
527 If defined internal UART1 (and not UART0) is used
528 as default U-Boot console.
529
530 - Boot Delay: CONFIG_BOOTDELAY - in seconds
531 Delay before automatically booting the default image;
532 set to -1 to disable autoboot.
533
534 See doc/README.autoboot for these options that
535 work with CONFIG_BOOTDELAY. None are required.
536 CONFIG_BOOT_RETRY_TIME
537 CONFIG_BOOT_RETRY_MIN
538 CONFIG_AUTOBOOT_KEYED
539 CONFIG_AUTOBOOT_PROMPT
540 CONFIG_AUTOBOOT_DELAY_STR
541 CONFIG_AUTOBOOT_STOP_STR
542 CONFIG_AUTOBOOT_DELAY_STR2
543 CONFIG_AUTOBOOT_STOP_STR2
544 CONFIG_ZERO_BOOTDELAY_CHECK
545 CONFIG_RESET_TO_RETRY
546
547 - Autoboot Command:
548 CONFIG_BOOTCOMMAND
549 Only needed when CONFIG_BOOTDELAY is enabled;
550 define a command string that is automatically executed
551 when no character is read on the console interface
552 within "Boot Delay" after reset.
553
554 CONFIG_BOOTARGS
555 This can be used to pass arguments to the bootm
556 command. The value of CONFIG_BOOTARGS goes into the
557 environment value "bootargs".
558
559 CONFIG_RAMBOOT and CONFIG_NFSBOOT
560 The value of these goes into the environment as
561 "ramboot" and "nfsboot" respectively, and can be used
562 as a convenience, when switching between booting from
563 RAM and NFS.
564
565 - Pre-Boot Commands:
566 CONFIG_PREBOOT
567
568 When this option is #defined, the existence of the
569 environment variable "preboot" will be checked
570 immediately before starting the CONFIG_BOOTDELAY
571 countdown and/or running the auto-boot command resp.
572 entering interactive mode.
573
574 This feature is especially useful when "preboot" is
575 automatically generated or modified. For an example
576 see the LWMON board specific code: here "preboot" is
577 modified when the user holds down a certain
578 combination of keys on the (special) keyboard when
579 booting the systems
580
581 - Serial Download Echo Mode:
582 CONFIG_LOADS_ECHO
583 If defined to 1, all characters received during a
584 serial download (using the "loads" command) are
585 echoed back. This might be needed by some terminal
586 emulations (like "cu"), but may as well just take
587 time on others. This setting #define's the initial
588 value of the "loads_echo" environment variable.
589
590 - Kgdb Serial Baudrate: (if CONFIG_CMD_KGDB is defined)
591 CONFIG_KGDB_BAUDRATE
592 Select one of the baudrates listed in
593 CONFIG_SYS_BAUDRATE_TABLE, see below.
594
595 - Monitor Functions:
596 Monitor commands can be included or excluded
597 from the build by using the #include files
598 "config_cmd_all.h" and #undef'ing unwanted
599 commands, or using "config_cmd_default.h"
600 and augmenting with additional #define's
601 for wanted commands.
602
603 The default command configuration includes all commands
604 except those marked below with a "*".
605
606 CONFIG_CMD_ASKENV * ask for env variable
607 CONFIG_CMD_BDI bdinfo
608 CONFIG_CMD_BEDBUG * Include BedBug Debugger
609 CONFIG_CMD_BMP * BMP support
610 CONFIG_CMD_BSP * Board specific commands
611 CONFIG_CMD_BOOTD bootd
612 CONFIG_CMD_CACHE * icache, dcache
613 CONFIG_CMD_CONSOLE coninfo
614 CONFIG_CMD_DATE * support for RTC, date/time...
615 CONFIG_CMD_DHCP * DHCP support
616 CONFIG_CMD_DIAG * Diagnostics
617 CONFIG_CMD_DS4510 * ds4510 I2C gpio commands
618 CONFIG_CMD_DS4510_INFO * ds4510 I2C info command
619 CONFIG_CMD_DS4510_MEM * ds4510 I2C eeprom/sram commansd
620 CONFIG_CMD_DS4510_RST * ds4510 I2C rst command
621 CONFIG_CMD_DTT * Digital Therm and Thermostat
622 CONFIG_CMD_ECHO echo arguments
623 CONFIG_CMD_EDITENV edit env variable
624 CONFIG_CMD_EEPROM * EEPROM read/write support
625 CONFIG_CMD_ELF * bootelf, bootvx
626 CONFIG_CMD_SAVEENV saveenv
627 CONFIG_CMD_FDC * Floppy Disk Support
628 CONFIG_CMD_FAT * FAT partition support
629 CONFIG_CMD_FDOS * Dos diskette Support
630 CONFIG_CMD_FLASH flinfo, erase, protect
631 CONFIG_CMD_FPGA FPGA device initialization support
632 CONFIG_CMD_HWFLOW * RTS/CTS hw flow control
633 CONFIG_CMD_I2C * I2C serial bus support
634 CONFIG_CMD_IDE * IDE harddisk support
635 CONFIG_CMD_IMI iminfo
636 CONFIG_CMD_IMLS List all found images
637 CONFIG_CMD_IMMAP * IMMR dump support
638 CONFIG_CMD_IRQ * irqinfo
639 CONFIG_CMD_ITEST Integer/string test of 2 values
640 CONFIG_CMD_JFFS2 * JFFS2 Support
641 CONFIG_CMD_KGDB * kgdb
642 CONFIG_CMD_LOADB loadb
643 CONFIG_CMD_LOADS loads
644 CONFIG_CMD_MD5SUM print md5 message digest
645 (requires CONFIG_CMD_MEMORY and CONFIG_MD5)
646 CONFIG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
647 loop, loopw, mtest
648 CONFIG_CMD_MISC Misc functions like sleep etc
649 CONFIG_CMD_MMC * MMC memory mapped support
650 CONFIG_CMD_MII * MII utility commands
651 CONFIG_CMD_MTDPARTS * MTD partition support
652 CONFIG_CMD_NAND * NAND support
653 CONFIG_CMD_NET bootp, tftpboot, rarpboot
654 CONFIG_CMD_PCA953X * PCA953x I2C gpio commands
655 CONFIG_CMD_PCA953X_INFO * PCA953x I2C gpio info command
656 CONFIG_CMD_PCI * pciinfo
657 CONFIG_CMD_PCMCIA * PCMCIA support
658 CONFIG_CMD_PING * send ICMP ECHO_REQUEST to network
659 host
660 CONFIG_CMD_PORTIO * Port I/O
661 CONFIG_CMD_REGINFO * Register dump
662 CONFIG_CMD_RUN run command in env variable
663 CONFIG_CMD_SAVES * save S record dump
664 CONFIG_CMD_SCSI * SCSI Support
665 CONFIG_CMD_SDRAM * print SDRAM configuration information
666 (requires CONFIG_CMD_I2C)
667 CONFIG_CMD_SETGETDCR Support for DCR Register access
668 (4xx only)
669 CONFIG_CMD_SHA1 print sha1 memory digest
670 (requires CONFIG_CMD_MEMORY)
671 CONFIG_CMD_SOURCE "source" command Support
672 CONFIG_CMD_SPI * SPI serial bus support
673 CONFIG_CMD_USB * USB support
674 CONFIG_CMD_VFD * VFD support (TRAB)
675 CONFIG_CMD_CDP * Cisco Discover Protocol support
676 CONFIG_CMD_FSL * Microblaze FSL support
677
678
679 EXAMPLE: If you want all functions except of network
680 support you can write:
681
682 #include "config_cmd_all.h"
683 #undef CONFIG_CMD_NET
684
685 Other Commands:
686 fdt (flattened device tree) command: CONFIG_OF_LIBFDT
687
688 Note: Don't enable the "icache" and "dcache" commands
689 (configuration option CONFIG_CMD_CACHE) unless you know
690 what you (and your U-Boot users) are doing. Data
691 cache cannot be enabled on systems like the 8xx or
692 8260 (where accesses to the IMMR region must be
693 uncached), and it cannot be disabled on all other
694 systems where we (mis-) use the data cache to hold an
695 initial stack and some data.
696
697
698 XXX - this list needs to get updated!
699
700 - Watchdog:
701 CONFIG_WATCHDOG
702 If this variable is defined, it enables watchdog
703 support. There must be support in the platform specific
704 code for a watchdog. For the 8xx and 8260 CPUs, the
705 SIU Watchdog feature is enabled in the SYPCR
706 register.
707
708 - U-Boot Version:
709 CONFIG_VERSION_VARIABLE
710 If this variable is defined, an environment variable
711 named "ver" is created by U-Boot showing the U-Boot
712 version as printed by the "version" command.
713 This variable is readonly.
714
715 - Real-Time Clock:
716
717 When CONFIG_CMD_DATE is selected, the type of the RTC
718 has to be selected, too. Define exactly one of the
719 following options:
720
721 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
722 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
723 CONFIG_RTC_MC13783 - use MC13783 RTC
724 CONFIG_RTC_MC146818 - use MC146818 RTC
725 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
726 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
727 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
728 CONFIG_RTC_DS164x - use Dallas DS164x RTC
729 CONFIG_RTC_ISL1208 - use Intersil ISL1208 RTC
730 CONFIG_RTC_MAX6900 - use Maxim, Inc. MAX6900 RTC
731 CONFIG_SYS_RTC_DS1337_NOOSC - Turn off the OSC output for DS1337
732
733 Note that if the RTC uses I2C, then the I2C interface
734 must also be configured. See I2C Support, below.
735
736 - GPIO Support:
737 CONFIG_PCA953X - use NXP's PCA953X series I2C GPIO
738 CONFIG_PCA953X_INFO - enable pca953x info command
739
740 Note that if the GPIO device uses I2C, then the I2C interface
741 must also be configured. See I2C Support, below.
742
743 - Timestamp Support:
744
745 When CONFIG_TIMESTAMP is selected, the timestamp
746 (date and time) of an image is printed by image
747 commands like bootm or iminfo. This option is
748 automatically enabled when you select CONFIG_CMD_DATE .
749
750 - Partition Support:
751 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
752 and/or CONFIG_ISO_PARTITION and/or CONFIG_EFI_PARTITION
753
754 If IDE or SCSI support is enabled (CONFIG_CMD_IDE or
755 CONFIG_CMD_SCSI) you must configure support for at
756 least one partition type as well.
757
758 - IDE Reset method:
759 CONFIG_IDE_RESET_ROUTINE - this is defined in several
760 board configurations files but used nowhere!
761
762 CONFIG_IDE_RESET - is this is defined, IDE Reset will
763 be performed by calling the function
764 ide_set_reset(int reset)
765 which has to be defined in a board specific file
766
767 - ATAPI Support:
768 CONFIG_ATAPI
769
770 Set this to enable ATAPI support.
771
772 - LBA48 Support
773 CONFIG_LBA48
774
775 Set this to enable support for disks larger than 137GB
776 Also look at CONFIG_SYS_64BIT_LBA ,CONFIG_SYS_64BIT_VSPRINTF and CONFIG_SYS_64BIT_STRTOUL
777 Whithout these , LBA48 support uses 32bit variables and will 'only'
778 support disks up to 2.1TB.
779
780 CONFIG_SYS_64BIT_LBA:
781 When enabled, makes the IDE subsystem use 64bit sector addresses.
782 Default is 32bit.
783
784 - SCSI Support:
785 At the moment only there is only support for the
786 SYM53C8XX SCSI controller; define
787 CONFIG_SCSI_SYM53C8XX to enable it.
788
789 CONFIG_SYS_SCSI_MAX_LUN [8], CONFIG_SYS_SCSI_MAX_SCSI_ID [7] and
790 CONFIG_SYS_SCSI_MAX_DEVICE [CONFIG_SYS_SCSI_MAX_SCSI_ID *
791 CONFIG_SYS_SCSI_MAX_LUN] can be adjusted to define the
792 maximum numbers of LUNs, SCSI ID's and target
793 devices.
794 CONFIG_SYS_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
795
796 - NETWORK Support (PCI):
797 CONFIG_E1000
798 Support for Intel 8254x gigabit chips.
799
800 CONFIG_E1000_FALLBACK_MAC
801 default MAC for empty EEPROM after production.
802
803 CONFIG_EEPRO100
804 Support for Intel 82557/82559/82559ER chips.
805 Optional CONFIG_EEPRO100_SROM_WRITE enables EEPROM
806 write routine for first time initialisation.
807
808 CONFIG_TULIP
809 Support for Digital 2114x chips.
810 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
811 modem chip initialisation (KS8761/QS6611).
812
813 CONFIG_NATSEMI
814 Support for National dp83815 chips.
815
816 CONFIG_NS8382X
817 Support for National dp8382[01] gigabit chips.
818
819 - NETWORK Support (other):
820
821 CONFIG_DRIVER_LAN91C96
822 Support for SMSC's LAN91C96 chips.
823
824 CONFIG_LAN91C96_BASE
825 Define this to hold the physical address
826 of the LAN91C96's I/O space
827
828 CONFIG_LAN91C96_USE_32_BIT
829 Define this to enable 32 bit addressing
830
831 CONFIG_DRIVER_SMC91111
832 Support for SMSC's LAN91C111 chip
833
834 CONFIG_SMC91111_BASE
835 Define this to hold the physical address
836 of the device (I/O space)
837
838 CONFIG_SMC_USE_32_BIT
839 Define this if data bus is 32 bits
840
841 CONFIG_SMC_USE_IOFUNCS
842 Define this to use i/o functions instead of macros
843 (some hardware wont work with macros)
844
845 CONFIG_DRIVER_SMC911X
846 Support for SMSC's LAN911x and LAN921x chips
847
848 CONFIG_DRIVER_SMC911X_BASE
849 Define this to hold the physical address
850 of the device (I/O space)
851
852 CONFIG_DRIVER_SMC911X_32_BIT
853 Define this if data bus is 32 bits
854
855 CONFIG_DRIVER_SMC911X_16_BIT
856 Define this if data bus is 16 bits. If your processor
857 automatically converts one 32 bit word to two 16 bit
858 words you may also try CONFIG_DRIVER_SMC911X_32_BIT.
859
860 - USB Support:
861 At the moment only the UHCI host controller is
862 supported (PIP405, MIP405, MPC5200); define
863 CONFIG_USB_UHCI to enable it.
864 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
865 and define CONFIG_USB_STORAGE to enable the USB
866 storage devices.
867 Note:
868 Supported are USB Keyboards and USB Floppy drives
869 (TEAC FD-05PUB).
870 MPC5200 USB requires additional defines:
871 CONFIG_USB_CLOCK
872 for 528 MHz Clock: 0x0001bbbb
873 CONFIG_PSC3_USB
874 for USB on PSC3
875 CONFIG_USB_CONFIG
876 for differential drivers: 0x00001000
877 for single ended drivers: 0x00005000
878 for differential drivers on PSC3: 0x00000100
879 for single ended drivers on PSC3: 0x00004100
880 CONFIG_SYS_USB_EVENT_POLL
881 May be defined to allow interrupt polling
882 instead of using asynchronous interrupts
883
884 - USB Device:
885 Define the below if you wish to use the USB console.
886 Once firmware is rebuilt from a serial console issue the
887 command "setenv stdin usbtty; setenv stdout usbtty" and
888 attach your USB cable. The Unix command "dmesg" should print
889 it has found a new device. The environment variable usbtty
890 can be set to gserial or cdc_acm to enable your device to
891 appear to a USB host as a Linux gserial device or a
892 Common Device Class Abstract Control Model serial device.
893 If you select usbtty = gserial you should be able to enumerate
894 a Linux host by
895 # modprobe usbserial vendor=0xVendorID product=0xProductID
896 else if using cdc_acm, simply setting the environment
897 variable usbtty to be cdc_acm should suffice. The following
898 might be defined in YourBoardName.h
899
900 CONFIG_USB_DEVICE
901 Define this to build a UDC device
902
903 CONFIG_USB_TTY
904 Define this to have a tty type of device available to
905 talk to the UDC device
906
907 CONFIG_SYS_CONSOLE_IS_IN_ENV
908 Define this if you want stdin, stdout &/or stderr to
909 be set to usbtty.
910
911 mpc8xx:
912 CONFIG_SYS_USB_EXTC_CLK 0xBLAH
913 Derive USB clock from external clock "blah"
914 - CONFIG_SYS_USB_EXTC_CLK 0x02
915
916 CONFIG_SYS_USB_BRG_CLK 0xBLAH
917 Derive USB clock from brgclk
918 - CONFIG_SYS_USB_BRG_CLK 0x04
919
920 If you have a USB-IF assigned VendorID then you may wish to
921 define your own vendor specific values either in BoardName.h
922 or directly in usbd_vendor_info.h. If you don't define
923 CONFIG_USBD_MANUFACTURER, CONFIG_USBD_PRODUCT_NAME,
924 CONFIG_USBD_VENDORID and CONFIG_USBD_PRODUCTID, then U-Boot
925 should pretend to be a Linux device to it's target host.
926
927 CONFIG_USBD_MANUFACTURER
928 Define this string as the name of your company for
929 - CONFIG_USBD_MANUFACTURER "my company"
930
931 CONFIG_USBD_PRODUCT_NAME
932 Define this string as the name of your product
933 - CONFIG_USBD_PRODUCT_NAME "acme usb device"
934
935 CONFIG_USBD_VENDORID
936 Define this as your assigned Vendor ID from the USB
937 Implementors Forum. This *must* be a genuine Vendor ID
938 to avoid polluting the USB namespace.
939 - CONFIG_USBD_VENDORID 0xFFFF
940
941 CONFIG_USBD_PRODUCTID
942 Define this as the unique Product ID
943 for your device
944 - CONFIG_USBD_PRODUCTID 0xFFFF
945
946
947 - MMC Support:
948 The MMC controller on the Intel PXA is supported. To
949 enable this define CONFIG_MMC. The MMC can be
950 accessed from the boot prompt by mapping the device
951 to physical memory similar to flash. Command line is
952 enabled with CONFIG_CMD_MMC. The MMC driver also works with
953 the FAT fs. This is enabled with CONFIG_CMD_FAT.
954
955 - Journaling Flash filesystem support:
956 CONFIG_JFFS2_NAND, CONFIG_JFFS2_NAND_OFF, CONFIG_JFFS2_NAND_SIZE,
957 CONFIG_JFFS2_NAND_DEV
958 Define these for a default partition on a NAND device
959
960 CONFIG_SYS_JFFS2_FIRST_SECTOR,
961 CONFIG_SYS_JFFS2_FIRST_BANK, CONFIG_SYS_JFFS2_NUM_BANKS
962 Define these for a default partition on a NOR device
963
964 CONFIG_SYS_JFFS_CUSTOM_PART
965 Define this to create an own partition. You have to provide a
966 function struct part_info* jffs2_part_info(int part_num)
967
968 If you define only one JFFS2 partition you may also want to
969 #define CONFIG_SYS_JFFS_SINGLE_PART 1
970 to disable the command chpart. This is the default when you
971 have not defined a custom partition
972
973 - Keyboard Support:
974 CONFIG_ISA_KEYBOARD
975
976 Define this to enable standard (PC-Style) keyboard
977 support
978
979 CONFIG_I8042_KBD
980 Standard PC keyboard driver with US (is default) and
981 GERMAN key layout (switch via environment 'keymap=de') support.
982 Export function i8042_kbd_init, i8042_tstc and i8042_getc
983 for cfb_console. Supports cursor blinking.
984
985 - Video support:
986 CONFIG_VIDEO
987
988 Define this to enable video support (for output to
989 video).
990
991 CONFIG_VIDEO_CT69000
992
993 Enable Chips & Technologies 69000 Video chip
994
995 CONFIG_VIDEO_SMI_LYNXEM
996 Enable Silicon Motion SMI 712/710/810 Video chip. The
997 video output is selected via environment 'videoout'
998 (1 = LCD and 2 = CRT). If videoout is undefined, CRT is
999 assumed.
1000
1001 For the CT69000 and SMI_LYNXEM drivers, videomode is
1002 selected via environment 'videomode'. Two different ways
1003 are possible:
1004 - "videomode=num" 'num' is a standard LiLo mode numbers.
1005 Following standard modes are supported (* is default):
1006
1007 Colors 640x480 800x600 1024x768 1152x864 1280x1024
1008 -------------+---------------------------------------------
1009 8 bits | 0x301* 0x303 0x305 0x161 0x307
1010 15 bits | 0x310 0x313 0x316 0x162 0x319
1011 16 bits | 0x311 0x314 0x317 0x163 0x31A
1012 24 bits | 0x312 0x315 0x318 ? 0x31B
1013 -------------+---------------------------------------------
1014 (i.e. setenv videomode 317; saveenv; reset;)
1015
1016 - "videomode=bootargs" all the video parameters are parsed
1017 from the bootargs. (See drivers/video/videomodes.c)
1018
1019
1020 CONFIG_VIDEO_SED13806
1021 Enable Epson SED13806 driver. This driver supports 8bpp
1022 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
1023 or CONFIG_VIDEO_SED13806_16BPP
1024
1025 - Keyboard Support:
1026 CONFIG_KEYBOARD
1027
1028 Define this to enable a custom keyboard support.
1029 This simply calls drv_keyboard_init() which must be
1030 defined in your board-specific files.
1031 The only board using this so far is RBC823.
1032
1033 - LCD Support: CONFIG_LCD
1034
1035 Define this to enable LCD support (for output to LCD
1036 display); also select one of the supported displays
1037 by defining one of these:
1038
1039 CONFIG_ATMEL_LCD:
1040
1041 HITACHI TX09D70VM1CCA, 3.5", 240x320.
1042
1043 CONFIG_NEC_NL6448AC33:
1044
1045 NEC NL6448AC33-18. Active, color, single scan.
1046
1047 CONFIG_NEC_NL6448BC20
1048
1049 NEC NL6448BC20-08. 6.5", 640x480.
1050 Active, color, single scan.
1051
1052 CONFIG_NEC_NL6448BC33_54
1053
1054 NEC NL6448BC33-54. 10.4", 640x480.
1055 Active, color, single scan.
1056
1057 CONFIG_SHARP_16x9
1058
1059 Sharp 320x240. Active, color, single scan.
1060 It isn't 16x9, and I am not sure what it is.
1061
1062 CONFIG_SHARP_LQ64D341
1063
1064 Sharp LQ64D341 display, 640x480.
1065 Active, color, single scan.
1066
1067 CONFIG_HLD1045
1068
1069 HLD1045 display, 640x480.
1070 Active, color, single scan.
1071
1072 CONFIG_OPTREX_BW
1073
1074 Optrex CBL50840-2 NF-FW 99 22 M5
1075 or
1076 Hitachi LMG6912RPFC-00T
1077 or
1078 Hitachi SP14Q002
1079
1080 320x240. Black & white.
1081
1082 Normally display is black on white background; define
1083 CONFIG_SYS_WHITE_ON_BLACK to get it inverted.
1084
1085 - Splash Screen Support: CONFIG_SPLASH_SCREEN
1086
1087 If this option is set, the environment is checked for
1088 a variable "splashimage". If found, the usual display
1089 of logo, copyright and system information on the LCD
1090 is suppressed and the BMP image at the address
1091 specified in "splashimage" is loaded instead. The
1092 console is redirected to the "nulldev", too. This
1093 allows for a "silent" boot where a splash screen is
1094 loaded very quickly after power-on.
1095
1096 CONFIG_SPLASH_SCREEN_ALIGN
1097
1098 If this option is set the splash image can be freely positioned
1099 on the screen. Environment variable "splashpos" specifies the
1100 position as "x,y". If a positive number is given it is used as
1101 number of pixel from left/top. If a negative number is given it
1102 is used as number of pixel from right/bottom. You can also
1103 specify 'm' for centering the image.
1104
1105 Example:
1106 setenv splashpos m,m
1107 => image at center of screen
1108
1109 setenv splashpos 30,20
1110 => image at x = 30 and y = 20
1111
1112 setenv splashpos -10,m
1113 => vertically centered image
1114 at x = dspWidth - bmpWidth - 9
1115
1116 - Gzip compressed BMP image support: CONFIG_VIDEO_BMP_GZIP
1117
1118 If this option is set, additionally to standard BMP
1119 images, gzipped BMP images can be displayed via the
1120 splashscreen support or the bmp command.
1121
1122 - Compression support:
1123 CONFIG_BZIP2
1124
1125 If this option is set, support for bzip2 compressed
1126 images is included. If not, only uncompressed and gzip
1127 compressed images are supported.
1128
1129 NOTE: the bzip2 algorithm requires a lot of RAM, so
1130 the malloc area (as defined by CONFIG_SYS_MALLOC_LEN) should
1131 be at least 4MB.
1132
1133 CONFIG_LZMA
1134
1135 If this option is set, support for lzma compressed
1136 images is included.
1137
1138 Note: The LZMA algorithm adds between 2 and 4KB of code and it
1139 requires an amount of dynamic memory that is given by the
1140 formula:
1141
1142 (1846 + 768 << (lc + lp)) * sizeof(uint16)
1143
1144 Where lc and lp stand for, respectively, Literal context bits
1145 and Literal pos bits.
1146
1147 This value is upper-bounded by 14MB in the worst case. Anyway,
1148 for a ~4MB large kernel image, we have lc=3 and lp=0 for a
1149 total amount of (1846 + 768 << (3 + 0)) * 2 = ~41KB... that is
1150 a very small buffer.
1151
1152 Use the lzmainfo tool to determinate the lc and lp values and
1153 then calculate the amount of needed dynamic memory (ensuring
1154 the appropriate CONFIG_SYS_MALLOC_LEN value).
1155
1156 - MII/PHY support:
1157 CONFIG_PHY_ADDR
1158
1159 The address of PHY on MII bus.
1160
1161 CONFIG_PHY_CLOCK_FREQ (ppc4xx)
1162
1163 The clock frequency of the MII bus
1164
1165 CONFIG_PHY_GIGE
1166
1167 If this option is set, support for speed/duplex
1168 detection of gigabit PHY is included.
1169
1170 CONFIG_PHY_RESET_DELAY
1171
1172 Some PHY like Intel LXT971A need extra delay after
1173 reset before any MII register access is possible.
1174 For such PHY, set this option to the usec delay
1175 required. (minimum 300usec for LXT971A)
1176
1177 CONFIG_PHY_CMD_DELAY (ppc4xx)
1178
1179 Some PHY like Intel LXT971A need extra delay after
1180 command issued before MII status register can be read
1181
1182 - Ethernet address:
1183 CONFIG_ETHADDR
1184 CONFIG_ETH1ADDR
1185 CONFIG_ETH2ADDR
1186 CONFIG_ETH3ADDR
1187 CONFIG_ETH4ADDR
1188 CONFIG_ETH5ADDR
1189
1190 Define a default value for Ethernet address to use
1191 for the respective Ethernet interface, in case this
1192 is not determined automatically.
1193
1194 - IP address:
1195 CONFIG_IPADDR
1196
1197 Define a default value for the IP address to use for
1198 the default Ethernet interface, in case this is not
1199 determined through e.g. bootp.
1200
1201 - Server IP address:
1202 CONFIG_SERVERIP
1203
1204 Defines a default value for the IP address of a TFTP
1205 server to contact when using the "tftboot" command.
1206
1207 CONFIG_KEEP_SERVERADDR
1208
1209 Keeps the server's MAC address, in the env 'serveraddr'
1210 for passing to bootargs (like Linux's netconsole option)
1211
1212 - Multicast TFTP Mode:
1213 CONFIG_MCAST_TFTP
1214
1215 Defines whether you want to support multicast TFTP as per
1216 rfc-2090; for example to work with atftp. Lets lots of targets
1217 tftp down the same boot image concurrently. Note: the Ethernet
1218 driver in use must provide a function: mcast() to join/leave a
1219 multicast group.
1220
1221 CONFIG_BOOTP_RANDOM_DELAY
1222 - BOOTP Recovery Mode:
1223 CONFIG_BOOTP_RANDOM_DELAY
1224
1225 If you have many targets in a network that try to
1226 boot using BOOTP, you may want to avoid that all
1227 systems send out BOOTP requests at precisely the same
1228 moment (which would happen for instance at recovery
1229 from a power failure, when all systems will try to
1230 boot, thus flooding the BOOTP server. Defining
1231 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
1232 inserted before sending out BOOTP requests. The
1233 following delays are inserted then:
1234
1235 1st BOOTP request: delay 0 ... 1 sec
1236 2nd BOOTP request: delay 0 ... 2 sec
1237 3rd BOOTP request: delay 0 ... 4 sec
1238 4th and following
1239 BOOTP requests: delay 0 ... 8 sec
1240
1241 - DHCP Advanced Options:
1242 You can fine tune the DHCP functionality by defining
1243 CONFIG_BOOTP_* symbols:
1244
1245 CONFIG_BOOTP_SUBNETMASK
1246 CONFIG_BOOTP_GATEWAY
1247 CONFIG_BOOTP_HOSTNAME
1248 CONFIG_BOOTP_NISDOMAIN
1249 CONFIG_BOOTP_BOOTPATH
1250 CONFIG_BOOTP_BOOTFILESIZE
1251 CONFIG_BOOTP_DNS
1252 CONFIG_BOOTP_DNS2
1253 CONFIG_BOOTP_SEND_HOSTNAME
1254 CONFIG_BOOTP_NTPSERVER
1255 CONFIG_BOOTP_TIMEOFFSET
1256 CONFIG_BOOTP_VENDOREX
1257
1258 CONFIG_BOOTP_SERVERIP - TFTP server will be the serverip
1259 environment variable, not the BOOTP server.
1260
1261 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
1262 serverip from a DHCP server, it is possible that more
1263 than one DNS serverip is offered to the client.
1264 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
1265 serverip will be stored in the additional environment
1266 variable "dnsip2". The first DNS serverip is always
1267 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
1268 is defined.
1269
1270 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
1271 to do a dynamic update of a DNS server. To do this, they
1272 need the hostname of the DHCP requester.
1273 If CONFIG_BOOTP_SEND_HOSTNAME is defined, the content
1274 of the "hostname" environment variable is passed as
1275 option 12 to the DHCP server.
1276
1277 CONFIG_BOOTP_DHCP_REQUEST_DELAY
1278
1279 A 32bit value in microseconds for a delay between
1280 receiving a "DHCP Offer" and sending the "DHCP Request".
1281 This fixes a problem with certain DHCP servers that don't
1282 respond 100% of the time to a "DHCP request". E.g. On an
1283 AT91RM9200 processor running at 180MHz, this delay needed
1284 to be *at least* 15,000 usec before a Windows Server 2003
1285 DHCP server would reply 100% of the time. I recommend at
1286 least 50,000 usec to be safe. The alternative is to hope
1287 that one of the retries will be successful but note that
1288 the DHCP timeout and retry process takes a longer than
1289 this delay.
1290
1291 - CDP Options:
1292 CONFIG_CDP_DEVICE_ID
1293
1294 The device id used in CDP trigger frames.
1295
1296 CONFIG_CDP_DEVICE_ID_PREFIX
1297
1298 A two character string which is prefixed to the MAC address
1299 of the device.
1300
1301 CONFIG_CDP_PORT_ID
1302
1303 A printf format string which contains the ascii name of
1304 the port. Normally is set to "eth%d" which sets
1305 eth0 for the first Ethernet, eth1 for the second etc.
1306
1307 CONFIG_CDP_CAPABILITIES
1308
1309 A 32bit integer which indicates the device capabilities;
1310 0x00000010 for a normal host which does not forwards.
1311
1312 CONFIG_CDP_VERSION
1313
1314 An ascii string containing the version of the software.
1315
1316 CONFIG_CDP_PLATFORM
1317
1318 An ascii string containing the name of the platform.
1319
1320 CONFIG_CDP_TRIGGER
1321
1322 A 32bit integer sent on the trigger.
1323
1324 CONFIG_CDP_POWER_CONSUMPTION
1325
1326 A 16bit integer containing the power consumption of the
1327 device in .1 of milliwatts.
1328
1329 CONFIG_CDP_APPLIANCE_VLAN_TYPE
1330
1331 A byte containing the id of the VLAN.
1332
1333 - Status LED: CONFIG_STATUS_LED
1334
1335 Several configurations allow to display the current
1336 status using a LED. For instance, the LED will blink
1337 fast while running U-Boot code, stop blinking as
1338 soon as a reply to a BOOTP request was received, and
1339 start blinking slow once the Linux kernel is running
1340 (supported by a status LED driver in the Linux
1341 kernel). Defining CONFIG_STATUS_LED enables this
1342 feature in U-Boot.
1343
1344 - CAN Support: CONFIG_CAN_DRIVER
1345
1346 Defining CONFIG_CAN_DRIVER enables CAN driver support
1347 on those systems that support this (optional)
1348 feature, like the TQM8xxL modules.
1349
1350 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
1351
1352 These enable I2C serial bus commands. Defining either of
1353 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
1354 include the appropriate I2C driver for the selected CPU.
1355
1356 This will allow you to use i2c commands at the u-boot
1357 command line (as long as you set CONFIG_CMD_I2C in
1358 CONFIG_COMMANDS) and communicate with i2c based realtime
1359 clock chips. See common/cmd_i2c.c for a description of the
1360 command line interface.
1361
1362 CONFIG_HARD_I2C selects a hardware I2C controller.
1363
1364 CONFIG_SOFT_I2C configures u-boot to use a software (aka
1365 bit-banging) driver instead of CPM or similar hardware
1366 support for I2C.
1367
1368 There are several other quantities that must also be
1369 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1370
1371 In both cases you will need to define CONFIG_SYS_I2C_SPEED
1372 to be the frequency (in Hz) at which you wish your i2c bus
1373 to run and CONFIG_SYS_I2C_SLAVE to be the address of this node (ie
1374 the CPU's i2c node address).
1375
1376 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1377 sets the CPU up as a master node and so its address should
1378 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1379 p.16-473). So, set CONFIG_SYS_I2C_SLAVE to 0.
1380
1381 CONFIG_SYS_I2C_INIT_MPC5XXX
1382
1383 When a board is reset during an i2c bus transfer
1384 chips might think that the current transfer is still
1385 in progress. Reset the slave devices by sending start
1386 commands until the slave device responds.
1387
1388 That's all that's required for CONFIG_HARD_I2C.
1389
1390 If you use the software i2c interface (CONFIG_SOFT_I2C)
1391 then the following macros need to be defined (examples are
1392 from include/configs/lwmon.h):
1393
1394 I2C_INIT
1395
1396 (Optional). Any commands necessary to enable the I2C
1397 controller or configure ports.
1398
1399 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1400
1401 I2C_PORT
1402
1403 (Only for MPC8260 CPU). The I/O port to use (the code
1404 assumes both bits are on the same port). Valid values
1405 are 0..3 for ports A..D.
1406
1407 I2C_ACTIVE
1408
1409 The code necessary to make the I2C data line active
1410 (driven). If the data line is open collector, this
1411 define can be null.
1412
1413 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1414
1415 I2C_TRISTATE
1416
1417 The code necessary to make the I2C data line tri-stated
1418 (inactive). If the data line is open collector, this
1419 define can be null.
1420
1421 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1422
1423 I2C_READ
1424
1425 Code that returns TRUE if the I2C data line is high,
1426 FALSE if it is low.
1427
1428 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1429
1430 I2C_SDA(bit)
1431
1432 If <bit> is TRUE, sets the I2C data line high. If it
1433 is FALSE, it clears it (low).
1434
1435 eg: #define I2C_SDA(bit) \
1436 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1437 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1438
1439 I2C_SCL(bit)
1440
1441 If <bit> is TRUE, sets the I2C clock line high. If it
1442 is FALSE, it clears it (low).
1443
1444 eg: #define I2C_SCL(bit) \
1445 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1446 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1447
1448 I2C_DELAY
1449
1450 This delay is invoked four times per clock cycle so this
1451 controls the rate of data transfer. The data rate thus
1452 is 1 / (I2C_DELAY * 4). Often defined to be something
1453 like:
1454
1455 #define I2C_DELAY udelay(2)
1456
1457 CONFIG_SYS_I2C_INIT_BOARD
1458
1459 When a board is reset during an i2c bus transfer
1460 chips might think that the current transfer is still
1461 in progress. On some boards it is possible to access
1462 the i2c SCLK line directly, either by using the
1463 processor pin as a GPIO or by having a second pin
1464 connected to the bus. If this option is defined a
1465 custom i2c_init_board() routine in boards/xxx/board.c
1466 is run early in the boot sequence.
1467
1468 CONFIG_I2CFAST (PPC405GP|PPC405EP only)
1469
1470 This option enables configuration of bi_iic_fast[] flags
1471 in u-boot bd_info structure based on u-boot environment
1472 variable "i2cfast". (see also i2cfast)
1473
1474 CONFIG_I2C_MULTI_BUS
1475
1476 This option allows the use of multiple I2C buses, each of which
1477 must have a controller. At any point in time, only one bus is
1478 active. To switch to a different bus, use the 'i2c dev' command.
1479 Note that bus numbering is zero-based.
1480
1481 CONFIG_SYS_I2C_NOPROBES
1482
1483 This option specifies a list of I2C devices that will be skipped
1484 when the 'i2c probe' command is issued. If CONFIG_I2C_MULTI_BUS
1485 is set, specify a list of bus-device pairs. Otherwise, specify
1486 a 1D array of device addresses
1487
1488 e.g.
1489 #undef CONFIG_I2C_MULTI_BUS
1490 #define CONFIG_SYS_I2C_NOPROBES {0x50,0x68}
1491
1492 will skip addresses 0x50 and 0x68 on a board with one I2C bus
1493
1494 #define CONFIG_I2C_MULTI_BUS
1495 #define CONFIG_SYS_I2C_MULTI_NOPROBES {{0,0x50},{0,0x68},{1,0x54}}
1496
1497 will skip addresses 0x50 and 0x68 on bus 0 and address 0x54 on bus 1
1498
1499 CONFIG_SYS_SPD_BUS_NUM
1500
1501 If defined, then this indicates the I2C bus number for DDR SPD.
1502 If not defined, then U-Boot assumes that SPD is on I2C bus 0.
1503
1504 CONFIG_SYS_RTC_BUS_NUM
1505
1506 If defined, then this indicates the I2C bus number for the RTC.
1507 If not defined, then U-Boot assumes that RTC is on I2C bus 0.
1508
1509 CONFIG_SYS_DTT_BUS_NUM
1510
1511 If defined, then this indicates the I2C bus number for the DTT.
1512 If not defined, then U-Boot assumes that DTT is on I2C bus 0.
1513
1514 CONFIG_SYS_I2C_DTT_ADDR:
1515
1516 If defined, specifies the I2C address of the DTT device.
1517 If not defined, then U-Boot uses predefined value for
1518 specified DTT device.
1519
1520 CONFIG_FSL_I2C
1521
1522 Define this option if you want to use Freescale's I2C driver in
1523 drivers/i2c/fsl_i2c.c.
1524
1525 CONFIG_I2C_MUX
1526
1527 Define this option if you have I2C devices reached over 1 .. n
1528 I2C Muxes like the pca9544a. This option addes a new I2C
1529 Command "i2c bus [muxtype:muxaddr:muxchannel]" which adds a
1530 new I2C Bus to the existing I2C Busses. If you select the
1531 new Bus with "i2c dev", u-bbot sends first the commandos for
1532 the muxes to activate this new "bus".
1533
1534 CONFIG_I2C_MULTI_BUS must be also defined, to use this
1535 feature!
1536
1537 Example:
1538 Adding a new I2C Bus reached over 2 pca9544a muxes
1539 The First mux with address 70 and channel 6
1540 The Second mux with address 71 and channel 4
1541
1542 => i2c bus pca9544a:70:6:pca9544a:71:4
1543
1544 Use the "i2c bus" command without parameter, to get a list
1545 of I2C Busses with muxes:
1546
1547 => i2c bus
1548 Busses reached over muxes:
1549 Bus ID: 2
1550 reached over Mux(es):
1551 pca9544a@70 ch: 4
1552 Bus ID: 3
1553 reached over Mux(es):
1554 pca9544a@70 ch: 6
1555 pca9544a@71 ch: 4
1556 =>
1557
1558 If you now switch to the new I2C Bus 3 with "i2c dev 3"
1559 u-boot sends First the Commando to the mux@70 to enable
1560 channel 6, and then the Commando to the mux@71 to enable
1561 the channel 4.
1562
1563 After that, you can use the "normal" i2c commands as
1564 usual, to communicate with your I2C devices behind
1565 the 2 muxes.
1566
1567 This option is actually implemented for the bitbanging
1568 algorithm in common/soft_i2c.c and for the Hardware I2C
1569 Bus on the MPC8260. But it should be not so difficult
1570 to add this option to other architectures.
1571
1572 CONFIG_SOFT_I2C_READ_REPEATED_START
1573
1574 defining this will force the i2c_read() function in
1575 the soft_i2c driver to perform an I2C repeated start
1576 between writing the address pointer and reading the
1577 data. If this define is omitted the default behaviour
1578 of doing a stop-start sequence will be used. Most I2C
1579 devices can use either method, but some require one or
1580 the other.
1581
1582 - SPI Support: CONFIG_SPI
1583
1584 Enables SPI driver (so far only tested with
1585 SPI EEPROM, also an instance works with Crystal A/D and
1586 D/As on the SACSng board)
1587
1588 CONFIG_SPI_X
1589
1590 Enables extended (16-bit) SPI EEPROM addressing.
1591 (symmetrical to CONFIG_I2C_X)
1592
1593 CONFIG_SOFT_SPI
1594
1595 Enables a software (bit-bang) SPI driver rather than
1596 using hardware support. This is a general purpose
1597 driver that only requires three general I/O port pins
1598 (two outputs, one input) to function. If this is
1599 defined, the board configuration must define several
1600 SPI configuration items (port pins to use, etc). For
1601 an example, see include/configs/sacsng.h.
1602
1603 CONFIG_HARD_SPI
1604
1605 Enables a hardware SPI driver for general-purpose reads
1606 and writes. As with CONFIG_SOFT_SPI, the board configuration
1607 must define a list of chip-select function pointers.
1608 Currently supported on some MPC8xxx processors. For an
1609 example, see include/configs/mpc8349emds.h.
1610
1611 CONFIG_MXC_SPI
1612
1613 Enables the driver for the SPI controllers on i.MX and MXC
1614 SoCs. Currently only i.MX31 is supported.
1615
1616 - FPGA Support: CONFIG_FPGA
1617
1618 Enables FPGA subsystem.
1619
1620 CONFIG_FPGA_<vendor>
1621
1622 Enables support for specific chip vendors.
1623 (ALTERA, XILINX)
1624
1625 CONFIG_FPGA_<family>
1626
1627 Enables support for FPGA family.
1628 (SPARTAN2, SPARTAN3, VIRTEX2, CYCLONE2, ACEX1K, ACEX)
1629
1630 CONFIG_FPGA_COUNT
1631
1632 Specify the number of FPGA devices to support.
1633
1634 CONFIG_SYS_FPGA_PROG_FEEDBACK
1635
1636 Enable printing of hash marks during FPGA configuration.
1637
1638 CONFIG_SYS_FPGA_CHECK_BUSY
1639
1640 Enable checks on FPGA configuration interface busy
1641 status by the configuration function. This option
1642 will require a board or device specific function to
1643 be written.
1644
1645 CONFIG_FPGA_DELAY
1646
1647 If defined, a function that provides delays in the FPGA
1648 configuration driver.
1649
1650 CONFIG_SYS_FPGA_CHECK_CTRLC
1651 Allow Control-C to interrupt FPGA configuration
1652
1653 CONFIG_SYS_FPGA_CHECK_ERROR
1654
1655 Check for configuration errors during FPGA bitfile
1656 loading. For example, abort during Virtex II
1657 configuration if the INIT_B line goes low (which
1658 indicated a CRC error).
1659
1660 CONFIG_SYS_FPGA_WAIT_INIT
1661
1662 Maximum time to wait for the INIT_B line to deassert
1663 after PROB_B has been deasserted during a Virtex II
1664 FPGA configuration sequence. The default time is 500
1665 ms.
1666
1667 CONFIG_SYS_FPGA_WAIT_BUSY
1668
1669 Maximum time to wait for BUSY to deassert during
1670 Virtex II FPGA configuration. The default is 5 ms.
1671
1672 CONFIG_SYS_FPGA_WAIT_CONFIG
1673
1674 Time to wait after FPGA configuration. The default is
1675 200 ms.
1676
1677 - Configuration Management:
1678 CONFIG_IDENT_STRING
1679
1680 If defined, this string will be added to the U-Boot
1681 version information (U_BOOT_VERSION)
1682
1683 - Vendor Parameter Protection:
1684
1685 U-Boot considers the values of the environment
1686 variables "serial#" (Board Serial Number) and
1687 "ethaddr" (Ethernet Address) to be parameters that
1688 are set once by the board vendor / manufacturer, and
1689 protects these variables from casual modification by
1690 the user. Once set, these variables are read-only,
1691 and write or delete attempts are rejected. You can
1692 change this behaviour:
1693
1694 If CONFIG_ENV_OVERWRITE is #defined in your config
1695 file, the write protection for vendor parameters is
1696 completely disabled. Anybody can change or delete
1697 these parameters.
1698
1699 Alternatively, if you #define _both_ CONFIG_ETHADDR
1700 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1701 Ethernet address is installed in the environment,
1702 which can be changed exactly ONCE by the user. [The
1703 serial# is unaffected by this, i. e. it remains
1704 read-only.]
1705
1706 - Protected RAM:
1707 CONFIG_PRAM
1708
1709 Define this variable to enable the reservation of
1710 "protected RAM", i. e. RAM which is not overwritten
1711 by U-Boot. Define CONFIG_PRAM to hold the number of
1712 kB you want to reserve for pRAM. You can overwrite
1713 this default value by defining an environment
1714 variable "pram" to the number of kB you want to
1715 reserve. Note that the board info structure will
1716 still show the full amount of RAM. If pRAM is
1717 reserved, a new environment variable "mem" will
1718 automatically be defined to hold the amount of
1719 remaining RAM in a form that can be passed as boot
1720 argument to Linux, for instance like that:
1721
1722 setenv bootargs ... mem=\${mem}
1723 saveenv
1724
1725 This way you can tell Linux not to use this memory,
1726 either, which results in a memory region that will
1727 not be affected by reboots.
1728
1729 *WARNING* If your board configuration uses automatic
1730 detection of the RAM size, you must make sure that
1731 this memory test is non-destructive. So far, the
1732 following board configurations are known to be
1733 "pRAM-clean":
1734
1735 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1736 HERMES, IP860, RPXlite, LWMON, LANTEC,
1737 PCU_E, FLAGADM, TQM8260
1738
1739 - Error Recovery:
1740 CONFIG_PANIC_HANG
1741
1742 Define this variable to stop the system in case of a
1743 fatal error, so that you have to reset it manually.
1744 This is probably NOT a good idea for an embedded
1745 system where you want the system to reboot
1746 automatically as fast as possible, but it may be
1747 useful during development since you can try to debug
1748 the conditions that lead to the situation.
1749
1750 CONFIG_NET_RETRY_COUNT
1751
1752 This variable defines the number of retries for
1753 network operations like ARP, RARP, TFTP, or BOOTP
1754 before giving up the operation. If not defined, a
1755 default value of 5 is used.
1756
1757 CONFIG_ARP_TIMEOUT
1758
1759 Timeout waiting for an ARP reply in milliseconds.
1760
1761 - Command Interpreter:
1762 CONFIG_AUTO_COMPLETE
1763
1764 Enable auto completion of commands using TAB.
1765
1766 Note that this feature has NOT been implemented yet
1767 for the "hush" shell.
1768
1769
1770 CONFIG_SYS_HUSH_PARSER
1771
1772 Define this variable to enable the "hush" shell (from
1773 Busybox) as command line interpreter, thus enabling
1774 powerful command line syntax like
1775 if...then...else...fi conditionals or `&&' and '||'
1776 constructs ("shell scripts").
1777
1778 If undefined, you get the old, much simpler behaviour
1779 with a somewhat smaller memory footprint.
1780
1781
1782 CONFIG_SYS_PROMPT_HUSH_PS2
1783
1784 This defines the secondary prompt string, which is
1785 printed when the command interpreter needs more input
1786 to complete a command. Usually "> ".
1787
1788 Note:
1789
1790 In the current implementation, the local variables
1791 space and global environment variables space are
1792 separated. Local variables are those you define by
1793 simply typing `name=value'. To access a local
1794 variable later on, you have write `$name' or
1795 `${name}'; to execute the contents of a variable
1796 directly type `$name' at the command prompt.
1797
1798 Global environment variables are those you use
1799 setenv/printenv to work with. To run a command stored
1800 in such a variable, you need to use the run command,
1801 and you must not use the '$' sign to access them.
1802
1803 To store commands and special characters in a
1804 variable, please use double quotation marks
1805 surrounding the whole text of the variable, instead
1806 of the backslashes before semicolons and special
1807 symbols.
1808
1809 - Commandline Editing and History:
1810 CONFIG_CMDLINE_EDITING
1811
1812 Enable editing and History functions for interactive
1813 commandline input operations
1814
1815 - Default Environment:
1816 CONFIG_EXTRA_ENV_SETTINGS
1817
1818 Define this to contain any number of null terminated
1819 strings (variable = value pairs) that will be part of
1820 the default environment compiled into the boot image.
1821
1822 For example, place something like this in your
1823 board's config file:
1824
1825 #define CONFIG_EXTRA_ENV_SETTINGS \
1826 "myvar1=value1\0" \
1827 "myvar2=value2\0"
1828
1829 Warning: This method is based on knowledge about the
1830 internal format how the environment is stored by the
1831 U-Boot code. This is NOT an official, exported
1832 interface! Although it is unlikely that this format
1833 will change soon, there is no guarantee either.
1834 You better know what you are doing here.
1835
1836 Note: overly (ab)use of the default environment is
1837 discouraged. Make sure to check other ways to preset
1838 the environment like the "source" command or the
1839 boot command first.
1840
1841 - DataFlash Support:
1842 CONFIG_HAS_DATAFLASH
1843
1844 Defining this option enables DataFlash features and
1845 allows to read/write in Dataflash via the standard
1846 commands cp, md...
1847
1848 - SystemACE Support:
1849 CONFIG_SYSTEMACE
1850
1851 Adding this option adds support for Xilinx SystemACE
1852 chips attached via some sort of local bus. The address
1853 of the chip must also be defined in the
1854 CONFIG_SYS_SYSTEMACE_BASE macro. For example:
1855
1856 #define CONFIG_SYSTEMACE
1857 #define CONFIG_SYS_SYSTEMACE_BASE 0xf0000000
1858
1859 When SystemACE support is added, the "ace" device type
1860 becomes available to the fat commands, i.e. fatls.
1861
1862 - TFTP Fixed UDP Port:
1863 CONFIG_TFTP_PORT
1864
1865 If this is defined, the environment variable tftpsrcp
1866 is used to supply the TFTP UDP source port value.
1867 If tftpsrcp isn't defined, the normal pseudo-random port
1868 number generator is used.
1869
1870 Also, the environment variable tftpdstp is used to supply
1871 the TFTP UDP destination port value. If tftpdstp isn't
1872 defined, the normal port 69 is used.
1873
1874 The purpose for tftpsrcp is to allow a TFTP server to
1875 blindly start the TFTP transfer using the pre-configured
1876 target IP address and UDP port. This has the effect of
1877 "punching through" the (Windows XP) firewall, allowing
1878 the remainder of the TFTP transfer to proceed normally.
1879 A better solution is to properly configure the firewall,
1880 but sometimes that is not allowed.
1881
1882 - Show boot progress:
1883 CONFIG_SHOW_BOOT_PROGRESS
1884
1885 Defining this option allows to add some board-
1886 specific code (calling a user-provided function
1887 "show_boot_progress(int)") that enables you to show
1888 the system's boot progress on some display (for
1889 example, some LED's) on your board. At the moment,
1890 the following checkpoints are implemented:
1891
1892 - Automatic software updates via TFTP server
1893 CONFIG_UPDATE_TFTP
1894 CONFIG_UPDATE_TFTP_CNT_MAX
1895 CONFIG_UPDATE_TFTP_MSEC_MAX
1896
1897 These options enable and control the auto-update feature;
1898 for a more detailed description refer to doc/README.update.
1899
1900 - MTD Support (mtdparts command, UBI support)
1901 CONFIG_MTD_DEVICE
1902
1903 Adds the MTD device infrastructure from the Linux kernel.
1904 Needed for mtdparts command support.
1905
1906 CONFIG_MTD_PARTITIONS
1907
1908 Adds the MTD partitioning infrastructure from the Linux
1909 kernel. Needed for UBI support.
1910
1911 Legacy uImage format:
1912
1913 Arg Where When
1914 1 common/cmd_bootm.c before attempting to boot an image
1915 -1 common/cmd_bootm.c Image header has bad magic number
1916 2 common/cmd_bootm.c Image header has correct magic number
1917 -2 common/cmd_bootm.c Image header has bad checksum
1918 3 common/cmd_bootm.c Image header has correct checksum
1919 -3 common/cmd_bootm.c Image data has bad checksum
1920 4 common/cmd_bootm.c Image data has correct checksum
1921 -4 common/cmd_bootm.c Image is for unsupported architecture
1922 5 common/cmd_bootm.c Architecture check OK
1923 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi)
1924 6 common/cmd_bootm.c Image Type check OK
1925 -6 common/cmd_bootm.c gunzip uncompression error
1926 -7 common/cmd_bootm.c Unimplemented compression type
1927 7 common/cmd_bootm.c Uncompression OK
1928 8 common/cmd_bootm.c No uncompress/copy overwrite error
1929 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1930
1931 9 common/image.c Start initial ramdisk verification
1932 -10 common/image.c Ramdisk header has bad magic number
1933 -11 common/image.c Ramdisk header has bad checksum
1934 10 common/image.c Ramdisk header is OK
1935 -12 common/image.c Ramdisk data has bad checksum
1936 11 common/image.c Ramdisk data has correct checksum
1937 12 common/image.c Ramdisk verification complete, start loading
1938 -13 common/image.c Wrong Image Type (not PPC Linux ramdisk)
1939 13 common/image.c Start multifile image verification
1940 14 common/image.c No initial ramdisk, no multifile, continue.
1941
1942 15 lib_<arch>/bootm.c All preparation done, transferring control to OS
1943
1944 -30 lib_ppc/board.c Fatal error, hang the system
1945 -31 post/post.c POST test failed, detected by post_output_backlog()
1946 -32 post/post.c POST test failed, detected by post_run_single()
1947
1948 34 common/cmd_doc.c before loading a Image from a DOC device
1949 -35 common/cmd_doc.c Bad usage of "doc" command
1950 35 common/cmd_doc.c correct usage of "doc" command
1951 -36 common/cmd_doc.c No boot device
1952 36 common/cmd_doc.c correct boot device
1953 -37 common/cmd_doc.c Unknown Chip ID on boot device
1954 37 common/cmd_doc.c correct chip ID found, device available
1955 -38 common/cmd_doc.c Read Error on boot device
1956 38 common/cmd_doc.c reading Image header from DOC device OK
1957 -39 common/cmd_doc.c Image header has bad magic number
1958 39 common/cmd_doc.c Image header has correct magic number
1959 -40 common/cmd_doc.c Error reading Image from DOC device
1960 40 common/cmd_doc.c Image header has correct magic number
1961 41 common/cmd_ide.c before loading a Image from a IDE device
1962 -42 common/cmd_ide.c Bad usage of "ide" command
1963 42 common/cmd_ide.c correct usage of "ide" command
1964 -43 common/cmd_ide.c No boot device
1965 43 common/cmd_ide.c boot device found
1966 -44 common/cmd_ide.c Device not available
1967 44 common/cmd_ide.c Device available
1968 -45 common/cmd_ide.c wrong partition selected
1969 45 common/cmd_ide.c partition selected
1970 -46 common/cmd_ide.c Unknown partition table
1971 46 common/cmd_ide.c valid partition table found
1972 -47 common/cmd_ide.c Invalid partition type
1973 47 common/cmd_ide.c correct partition type
1974 -48 common/cmd_ide.c Error reading Image Header on boot device
1975 48 common/cmd_ide.c reading Image Header from IDE device OK
1976 -49 common/cmd_ide.c Image header has bad magic number
1977 49 common/cmd_ide.c Image header has correct magic number
1978 -50 common/cmd_ide.c Image header has bad checksum
1979 50 common/cmd_ide.c Image header has correct checksum
1980 -51 common/cmd_ide.c Error reading Image from IDE device
1981 51 common/cmd_ide.c reading Image from IDE device OK
1982 52 common/cmd_nand.c before loading a Image from a NAND device
1983 -53 common/cmd_nand.c Bad usage of "nand" command
1984 53 common/cmd_nand.c correct usage of "nand" command
1985 -54 common/cmd_nand.c No boot device
1986 54 common/cmd_nand.c boot device found
1987 -55 common/cmd_nand.c Unknown Chip ID on boot device
1988 55 common/cmd_nand.c correct chip ID found, device available
1989 -56 common/cmd_nand.c Error reading Image Header on boot device
1990 56 common/cmd_nand.c reading Image Header from NAND device OK
1991 -57 common/cmd_nand.c Image header has bad magic number
1992 57 common/cmd_nand.c Image header has correct magic number
1993 -58 common/cmd_nand.c Error reading Image from NAND device
1994 58 common/cmd_nand.c reading Image from NAND device OK
1995
1996 -60 common/env_common.c Environment has a bad CRC, using default
1997
1998 64 net/eth.c starting with Ethernet configuration.
1999 -64 net/eth.c no Ethernet found.
2000 65 net/eth.c Ethernet found.
2001
2002 -80 common/cmd_net.c usage wrong
2003 80 common/cmd_net.c before calling NetLoop()
2004 -81 common/cmd_net.c some error in NetLoop() occurred
2005 81 common/cmd_net.c NetLoop() back without error
2006 -82 common/cmd_net.c size == 0 (File with size 0 loaded)
2007 82 common/cmd_net.c trying automatic boot
2008 83 common/cmd_net.c running "source" command
2009 -83 common/cmd_net.c some error in automatic boot or "source" command
2010 84 common/cmd_net.c end without errors
2011
2012 FIT uImage format:
2013
2014 Arg Where When
2015 100 common/cmd_bootm.c Kernel FIT Image has correct format
2016 -100 common/cmd_bootm.c Kernel FIT Image has incorrect format
2017 101 common/cmd_bootm.c No Kernel subimage unit name, using configuration
2018 -101 common/cmd_bootm.c Can't get configuration for kernel subimage
2019 102 common/cmd_bootm.c Kernel unit name specified
2020 -103 common/cmd_bootm.c Can't get kernel subimage node offset
2021 103 common/cmd_bootm.c Found configuration node
2022 104 common/cmd_bootm.c Got kernel subimage node offset
2023 -104 common/cmd_bootm.c Kernel subimage hash verification failed
2024 105 common/cmd_bootm.c Kernel subimage hash verification OK
2025 -105 common/cmd_bootm.c Kernel subimage is for unsupported architecture
2026 106 common/cmd_bootm.c Architecture check OK
2027 -106 common/cmd_bootm.c Kernel subimage has wrong type
2028 107 common/cmd_bootm.c Kernel subimage type OK
2029 -107 common/cmd_bootm.c Can't get kernel subimage data/size
2030 108 common/cmd_bootm.c Got kernel subimage data/size
2031 -108 common/cmd_bootm.c Wrong image type (not legacy, FIT)
2032 -109 common/cmd_bootm.c Can't get kernel subimage type
2033 -110 common/cmd_bootm.c Can't get kernel subimage comp
2034 -111 common/cmd_bootm.c Can't get kernel subimage os
2035 -112 common/cmd_bootm.c Can't get kernel subimage load address
2036 -113 common/cmd_bootm.c Image uncompress/copy overwrite error
2037
2038 120 common/image.c Start initial ramdisk verification
2039 -120 common/image.c Ramdisk FIT image has incorrect format
2040 121 common/image.c Ramdisk FIT image has correct format
2041 122 common/image.c No ramdisk subimage unit name, using configuration
2042 -122 common/image.c Can't get configuration for ramdisk subimage
2043 123 common/image.c Ramdisk unit name specified
2044 -124 common/image.c Can't get ramdisk subimage node offset
2045 125 common/image.c Got ramdisk subimage node offset
2046 -125 common/image.c Ramdisk subimage hash verification failed
2047 126 common/image.c Ramdisk subimage hash verification OK
2048 -126 common/image.c Ramdisk subimage for unsupported architecture
2049 127 common/image.c Architecture check OK
2050 -127 common/image.c Can't get ramdisk subimage data/size
2051 128 common/image.c Got ramdisk subimage data/size
2052 129 common/image.c Can't get ramdisk load address
2053 -129 common/image.c Got ramdisk load address
2054
2055 -130 common/cmd_doc.c Incorrect FIT image format
2056 131 common/cmd_doc.c FIT image format OK
2057
2058 -140 common/cmd_ide.c Incorrect FIT image format
2059 141 common/cmd_ide.c FIT image format OK
2060
2061 -150 common/cmd_nand.c Incorrect FIT image format
2062 151 common/cmd_nand.c FIT image format OK
2063
2064
2065 Modem Support:
2066 --------------
2067
2068 [so far only for SMDK2400 and TRAB boards]
2069
2070 - Modem support enable:
2071 CONFIG_MODEM_SUPPORT
2072
2073 - RTS/CTS Flow control enable:
2074 CONFIG_HWFLOW
2075
2076 - Modem debug support:
2077 CONFIG_MODEM_SUPPORT_DEBUG
2078
2079 Enables debugging stuff (char screen[1024], dbg())
2080 for modem support. Useful only with BDI2000.
2081
2082 - Interrupt support (PPC):
2083
2084 There are common interrupt_init() and timer_interrupt()
2085 for all PPC archs. interrupt_init() calls interrupt_init_cpu()
2086 for CPU specific initialization. interrupt_init_cpu()
2087 should set decrementer_count to appropriate value. If
2088 CPU resets decrementer automatically after interrupt
2089 (ppc4xx) it should set decrementer_count to zero.
2090 timer_interrupt() calls timer_interrupt_cpu() for CPU
2091 specific handling. If board has watchdog / status_led
2092 / other_activity_monitor it works automatically from
2093 general timer_interrupt().
2094
2095 - General:
2096
2097 In the target system modem support is enabled when a
2098 specific key (key combination) is pressed during
2099 power-on. Otherwise U-Boot will boot normally
2100 (autoboot). The key_pressed() function is called from
2101 board_init(). Currently key_pressed() is a dummy
2102 function, returning 1 and thus enabling modem
2103 initialization.
2104
2105 If there are no modem init strings in the
2106 environment, U-Boot proceed to autoboot; the
2107 previous output (banner, info printfs) will be
2108 suppressed, though.
2109
2110 See also: doc/README.Modem
2111
2112
2113 Configuration Settings:
2114 -----------------------
2115
2116 - CONFIG_SYS_LONGHELP: Defined when you want long help messages included;
2117 undefine this when you're short of memory.
2118
2119 - CONFIG_SYS_HELP_CMD_WIDTH: Defined when you want to override the default
2120 width of the commands listed in the 'help' command output.
2121
2122 - CONFIG_SYS_PROMPT: This is what U-Boot prints on the console to
2123 prompt for user input.
2124
2125 - CONFIG_SYS_CBSIZE: Buffer size for input from the Console
2126
2127 - CONFIG_SYS_PBSIZE: Buffer size for Console output
2128
2129 - CONFIG_SYS_MAXARGS: max. Number of arguments accepted for monitor commands
2130
2131 - CONFIG_SYS_BARGSIZE: Buffer size for Boot Arguments which are passed to
2132 the application (usually a Linux kernel) when it is
2133 booted
2134
2135 - CONFIG_SYS_BAUDRATE_TABLE:
2136 List of legal baudrate settings for this board.
2137
2138 - CONFIG_SYS_CONSOLE_INFO_QUIET
2139 Suppress display of console information at boot.
2140
2141 - CONFIG_SYS_CONSOLE_IS_IN_ENV
2142 If the board specific function
2143 extern int overwrite_console (void);
2144 returns 1, the stdin, stderr and stdout are switched to the
2145 serial port, else the settings in the environment are used.
2146
2147 - CONFIG_SYS_CONSOLE_OVERWRITE_ROUTINE
2148 Enable the call to overwrite_console().
2149
2150 - CONFIG_SYS_CONSOLE_ENV_OVERWRITE
2151 Enable overwrite of previous console environment settings.
2152
2153 - CONFIG_SYS_MEMTEST_START, CONFIG_SYS_MEMTEST_END:
2154 Begin and End addresses of the area used by the
2155 simple memory test.
2156
2157 - CONFIG_SYS_ALT_MEMTEST:
2158 Enable an alternate, more extensive memory test.
2159
2160 - CONFIG_SYS_MEMTEST_SCRATCH:
2161 Scratch address used by the alternate memory test
2162 You only need to set this if address zero isn't writeable
2163
2164 - CONFIG_SYS_MEM_TOP_HIDE (PPC only):
2165 If CONFIG_SYS_MEM_TOP_HIDE is defined in the board config header,
2166 this specified memory area will get subtracted from the top
2167 (end) of RAM and won't get "touched" at all by U-Boot. By
2168 fixing up gd->ram_size the Linux kernel should gets passed
2169 the now "corrected" memory size and won't touch it either.
2170 This should work for arch/ppc and arch/powerpc. Only Linux
2171 board ports in arch/powerpc with bootwrapper support that
2172 recalculate the memory size from the SDRAM controller setup
2173 will have to get fixed in Linux additionally.
2174
2175 This option can be used as a workaround for the 440EPx/GRx
2176 CHIP 11 errata where the last 256 bytes in SDRAM shouldn't
2177 be touched.
2178
2179 WARNING: Please make sure that this value is a multiple of
2180 the Linux page size (normally 4k). If this is not the case,
2181 then the end address of the Linux memory will be located at a
2182 non page size aligned address and this could cause major
2183 problems.
2184
2185 - CONFIG_SYS_TFTP_LOADADDR:
2186 Default load address for network file downloads
2187
2188 - CONFIG_SYS_LOADS_BAUD_CHANGE:
2189 Enable temporary baudrate change while serial download
2190
2191 - CONFIG_SYS_SDRAM_BASE:
2192 Physical start address of SDRAM. _Must_ be 0 here.
2193
2194 - CONFIG_SYS_MBIO_BASE:
2195 Physical start address of Motherboard I/O (if using a
2196 Cogent motherboard)
2197
2198 - CONFIG_SYS_FLASH_BASE:
2199 Physical start address of Flash memory.
2200
2201 - CONFIG_SYS_MONITOR_BASE:
2202 Physical start address of boot monitor code (set by
2203 make config files to be same as the text base address
2204 (TEXT_BASE) used when linking) - same as
2205 CONFIG_SYS_FLASH_BASE when booting from flash.
2206
2207 - CONFIG_SYS_MONITOR_LEN:
2208 Size of memory reserved for monitor code, used to
2209 determine _at_compile_time_ (!) if the environment is
2210 embedded within the U-Boot image, or in a separate
2211 flash sector.
2212
2213 - CONFIG_SYS_MALLOC_LEN:
2214 Size of DRAM reserved for malloc() use.
2215
2216 - CONFIG_SYS_BOOTM_LEN:
2217 Normally compressed uImages are limited to an
2218 uncompressed size of 8 MBytes. If this is not enough,
2219 you can define CONFIG_SYS_BOOTM_LEN in your board config file
2220 to adjust this setting to your needs.
2221
2222 - CONFIG_SYS_BOOTMAPSZ:
2223 Maximum size of memory mapped by the startup code of
2224 the Linux kernel; all data that must be processed by
2225 the Linux kernel (bd_info, boot arguments, FDT blob if
2226 used) must be put below this limit, unless "bootm_low"
2227 enviroment variable is defined and non-zero. In such case
2228 all data for the Linux kernel must be between "bootm_low"
2229 and "bootm_low" + CONFIG_SYS_BOOTMAPSZ.
2230
2231 - CONFIG_SYS_MAX_FLASH_BANKS:
2232 Max number of Flash memory banks
2233
2234 - CONFIG_SYS_MAX_FLASH_SECT:
2235 Max number of sectors on a Flash chip
2236
2237 - CONFIG_SYS_FLASH_ERASE_TOUT:
2238 Timeout for Flash erase operations (in ms)
2239
2240 - CONFIG_SYS_FLASH_WRITE_TOUT:
2241 Timeout for Flash write operations (in ms)
2242
2243 - CONFIG_SYS_FLASH_LOCK_TOUT
2244 Timeout for Flash set sector lock bit operation (in ms)
2245
2246 - CONFIG_SYS_FLASH_UNLOCK_TOUT
2247 Timeout for Flash clear lock bits operation (in ms)
2248
2249 - CONFIG_SYS_FLASH_PROTECTION
2250 If defined, hardware flash sectors protection is used
2251 instead of U-Boot software protection.
2252
2253 - CONFIG_SYS_DIRECT_FLASH_TFTP:
2254
2255 Enable TFTP transfers directly to flash memory;
2256 without this option such a download has to be
2257 performed in two steps: (1) download to RAM, and (2)
2258 copy from RAM to flash.
2259
2260 The two-step approach is usually more reliable, since
2261 you can check if the download worked before you erase
2262 the flash, but in some situations (when system RAM is
2263 too limited to allow for a temporary copy of the
2264 downloaded image) this option may be very useful.
2265
2266 - CONFIG_SYS_FLASH_CFI:
2267 Define if the flash driver uses extra elements in the
2268 common flash structure for storing flash geometry.
2269
2270 - CONFIG_FLASH_CFI_DRIVER
2271 This option also enables the building of the cfi_flash driver
2272 in the drivers directory
2273
2274 - CONFIG_FLASH_CFI_MTD
2275 This option enables the building of the cfi_mtd driver
2276 in the drivers directory. The driver exports CFI flash
2277 to the MTD layer.
2278
2279 - CONFIG_SYS_FLASH_USE_BUFFER_WRITE
2280 Use buffered writes to flash.
2281
2282 - CONFIG_FLASH_SPANSION_S29WS_N
2283 s29ws-n MirrorBit flash has non-standard addresses for buffered
2284 write commands.
2285
2286 - CONFIG_SYS_FLASH_QUIET_TEST
2287 If this option is defined, the common CFI flash doesn't
2288 print it's warning upon not recognized FLASH banks. This
2289 is useful, if some of the configured banks are only
2290 optionally available.
2291
2292 - CONFIG_FLASH_SHOW_PROGRESS
2293 If defined (must be an integer), print out countdown
2294 digits and dots. Recommended value: 45 (9..1) for 80
2295 column displays, 15 (3..1) for 40 column displays.
2296
2297 - CONFIG_SYS_RX_ETH_BUFFER:
2298 Defines the number of Ethernet receive buffers. On some
2299 Ethernet controllers it is recommended to set this value
2300 to 8 or even higher (EEPRO100 or 405 EMAC), since all
2301 buffers can be full shortly after enabling the interface
2302 on high Ethernet traffic.
2303 Defaults to 4 if not defined.
2304
2305 The following definitions that deal with the placement and management
2306 of environment data (variable area); in general, we support the
2307 following configurations:
2308
2309 - CONFIG_ENV_IS_IN_FLASH:
2310
2311 Define this if the environment is in flash memory.
2312
2313 a) The environment occupies one whole flash sector, which is
2314 "embedded" in the text segment with the U-Boot code. This
2315 happens usually with "bottom boot sector" or "top boot
2316 sector" type flash chips, which have several smaller
2317 sectors at the start or the end. For instance, such a
2318 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
2319 such a case you would place the environment in one of the
2320 4 kB sectors - with U-Boot code before and after it. With
2321 "top boot sector" type flash chips, you would put the
2322 environment in one of the last sectors, leaving a gap
2323 between U-Boot and the environment.
2324
2325 - CONFIG_ENV_OFFSET:
2326
2327 Offset of environment data (variable area) to the
2328 beginning of flash memory; for instance, with bottom boot
2329 type flash chips the second sector can be used: the offset
2330 for this sector is given here.
2331
2332 CONFIG_ENV_OFFSET is used relative to CONFIG_SYS_FLASH_BASE.
2333
2334 - CONFIG_ENV_ADDR:
2335
2336 This is just another way to specify the start address of
2337 the flash sector containing the environment (instead of
2338 CONFIG_ENV_OFFSET).
2339
2340 - CONFIG_ENV_SECT_SIZE:
2341
2342 Size of the sector containing the environment.
2343
2344
2345 b) Sometimes flash chips have few, equal sized, BIG sectors.
2346 In such a case you don't want to spend a whole sector for
2347 the environment.
2348
2349 - CONFIG_ENV_SIZE:
2350
2351 If you use this in combination with CONFIG_ENV_IS_IN_FLASH
2352 and CONFIG_ENV_SECT_SIZE, you can specify to use only a part
2353 of this flash sector for the environment. This saves
2354 memory for the RAM copy of the environment.
2355
2356 It may also save flash memory if you decide to use this
2357 when your environment is "embedded" within U-Boot code,
2358 since then the remainder of the flash sector could be used
2359 for U-Boot code. It should be pointed out that this is
2360 STRONGLY DISCOURAGED from a robustness point of view:
2361 updating the environment in flash makes it always
2362 necessary to erase the WHOLE sector. If something goes
2363 wrong before the contents has been restored from a copy in
2364 RAM, your target system will be dead.
2365
2366 - CONFIG_ENV_ADDR_REDUND
2367 CONFIG_ENV_SIZE_REDUND
2368
2369 These settings describe a second storage area used to hold
2370 a redundant copy of the environment data, so that there is
2371 a valid backup copy in case there is a power failure during
2372 a "saveenv" operation.
2373
2374 BE CAREFUL! Any changes to the flash layout, and some changes to the
2375 source code will make it necessary to adapt <board>/u-boot.lds*
2376 accordingly!
2377
2378
2379 - CONFIG_ENV_IS_IN_NVRAM:
2380
2381 Define this if you have some non-volatile memory device
2382 (NVRAM, battery buffered SRAM) which you want to use for the
2383 environment.
2384
2385 - CONFIG_ENV_ADDR:
2386 - CONFIG_ENV_SIZE:
2387
2388 These two #defines are used to determine the memory area you
2389 want to use for environment. It is assumed that this memory
2390 can just be read and written to, without any special
2391 provision.
2392
2393 BE CAREFUL! The first access to the environment happens quite early
2394 in U-Boot initalization (when we try to get the setting of for the
2395 console baudrate). You *MUST* have mapped your NVRAM area then, or
2396 U-Boot will hang.
2397
2398 Please note that even with NVRAM we still use a copy of the
2399 environment in RAM: we could work on NVRAM directly, but we want to
2400 keep settings there always unmodified except somebody uses "saveenv"
2401 to save the current settings.
2402
2403
2404 - CONFIG_ENV_IS_IN_EEPROM:
2405
2406 Use this if you have an EEPROM or similar serial access
2407 device and a driver for it.
2408
2409 - CONFIG_ENV_OFFSET:
2410 - CONFIG_ENV_SIZE:
2411
2412 These two #defines specify the offset and size of the
2413 environment area within the total memory of your EEPROM.
2414
2415 - CONFIG_SYS_I2C_EEPROM_ADDR:
2416 If defined, specified the chip address of the EEPROM device.
2417 The default address is zero.
2418
2419 - CONFIG_SYS_EEPROM_PAGE_WRITE_BITS:
2420 If defined, the number of bits used to address bytes in a
2421 single page in the EEPROM device. A 64 byte page, for example
2422 would require six bits.
2423
2424 - CONFIG_SYS_EEPROM_PAGE_WRITE_DELAY_MS:
2425 If defined, the number of milliseconds to delay between
2426 page writes. The default is zero milliseconds.
2427
2428 - CONFIG_SYS_I2C_EEPROM_ADDR_LEN:
2429 The length in bytes of the EEPROM memory array address. Note
2430 that this is NOT the chip address length!
2431
2432 - CONFIG_SYS_I2C_EEPROM_ADDR_OVERFLOW:
2433 EEPROM chips that implement "address overflow" are ones
2434 like Catalyst 24WC04/08/16 which has 9/10/11 bits of
2435 address and the extra bits end up in the "chip address" bit
2436 slots. This makes a 24WC08 (1Kbyte) chip look like four 256
2437 byte chips.
2438
2439 Note that we consider the length of the address field to
2440 still be one byte because the extra address bits are hidden
2441 in the chip address.
2442
2443 - CONFIG_SYS_EEPROM_SIZE:
2444 The size in bytes of the EEPROM device.
2445
2446
2447 - CONFIG_ENV_IS_IN_DATAFLASH:
2448
2449 Define this if you have a DataFlash memory device which you
2450 want to use for the environment.
2451
2452 - CONFIG_ENV_OFFSET:
2453 - CONFIG_ENV_ADDR:
2454 - CONFIG_ENV_SIZE:
2455
2456 These three #defines specify the offset and size of the
2457 environment area within the total memory of your DataFlash placed
2458 at the specified address.
2459
2460 - CONFIG_ENV_IS_IN_NAND:
2461
2462 Define this if you have a NAND device which you want to use
2463 for the environment.
2464
2465 - CONFIG_ENV_OFFSET:
2466 - CONFIG_ENV_SIZE:
2467
2468 These two #defines specify the offset and size of the environment
2469 area within the first NAND device.
2470
2471 - CONFIG_ENV_OFFSET_REDUND
2472
2473 This setting describes a second storage area of CONFIG_ENV_SIZE
2474 size used to hold a redundant copy of the environment data,
2475 so that there is a valid backup copy in case there is a
2476 power failure during a "saveenv" operation.
2477
2478 Note: CONFIG_ENV_OFFSET and CONFIG_ENV_OFFSET_REDUND must be aligned
2479 to a block boundary, and CONFIG_ENV_SIZE must be a multiple of
2480 the NAND devices block size.
2481
2482 - CONFIG_NAND_ENV_DST
2483
2484 Defines address in RAM to which the nand_spl code should copy the
2485 environment. If redundant environment is used, it will be copied to
2486 CONFIG_NAND_ENV_DST + CONFIG_ENV_SIZE.
2487
2488 - CONFIG_SYS_SPI_INIT_OFFSET
2489
2490 Defines offset to the initial SPI buffer area in DPRAM. The
2491 area is used at an early stage (ROM part) if the environment
2492 is configured to reside in the SPI EEPROM: We need a 520 byte
2493 scratch DPRAM area. It is used between the two initialization
2494 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
2495 to be a good choice since it makes it far enough from the
2496 start of the data area as well as from the stack pointer.
2497
2498 Please note that the environment is read-only until the monitor
2499 has been relocated to RAM and a RAM copy of the environment has been
2500 created; also, when using EEPROM you will have to use getenv_r()
2501 until then to read environment variables.
2502
2503 The environment is protected by a CRC32 checksum. Before the monitor
2504 is relocated into RAM, as a result of a bad CRC you will be working
2505 with the compiled-in default environment - *silently*!!! [This is
2506 necessary, because the first environment variable we need is the
2507 "baudrate" setting for the console - if we have a bad CRC, we don't
2508 have any device yet where we could complain.]
2509
2510 Note: once the monitor has been relocated, then it will complain if
2511 the default environment is used; a new CRC is computed as soon as you
2512 use the "saveenv" command to store a valid environment.
2513
2514 - CONFIG_SYS_FAULT_ECHO_LINK_DOWN:
2515 Echo the inverted Ethernet link state to the fault LED.
2516
2517 Note: If this option is active, then CONFIG_SYS_FAULT_MII_ADDR
2518 also needs to be defined.
2519
2520 - CONFIG_SYS_FAULT_MII_ADDR:
2521 MII address of the PHY to check for the Ethernet link state.
2522
2523 - CONFIG_SYS_64BIT_VSPRINTF:
2524 Makes vsprintf (and all *printf functions) support printing
2525 of 64bit values by using the L quantifier
2526
2527 - CONFIG_SYS_64BIT_STRTOUL:
2528 Adds simple_strtoull that returns a 64bit value
2529
2530 - CONFIG_NS16550_MIN_FUNCTIONS:
2531 Define this if you desire to only have use of the NS16550_init
2532 and NS16550_putc functions for the serial driver located at
2533 drivers/serial/ns16550.c. This option is useful for saving
2534 space for already greatly restricted images, including but not
2535 limited to NAND_SPL configurations.
2536
2537 Low Level (hardware related) configuration options:
2538 ---------------------------------------------------
2539
2540 - CONFIG_SYS_CACHELINE_SIZE:
2541 Cache Line Size of the CPU.
2542
2543 - CONFIG_SYS_DEFAULT_IMMR:
2544 Default address of the IMMR after system reset.
2545
2546 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
2547 and RPXsuper) to be able to adjust the position of
2548 the IMMR register after a reset.
2549
2550 - Floppy Disk Support:
2551 CONFIG_SYS_FDC_DRIVE_NUMBER
2552
2553 the default drive number (default value 0)
2554
2555 CONFIG_SYS_ISA_IO_STRIDE
2556
2557 defines the spacing between FDC chipset registers
2558 (default value 1)
2559
2560 CONFIG_SYS_ISA_IO_OFFSET
2561
2562 defines the offset of register from address. It
2563 depends on which part of the data bus is connected to
2564 the FDC chipset. (default value 0)
2565
2566 If CONFIG_SYS_ISA_IO_STRIDE CONFIG_SYS_ISA_IO_OFFSET and
2567 CONFIG_SYS_FDC_DRIVE_NUMBER are undefined, they take their
2568 default value.
2569
2570 if CONFIG_SYS_FDC_HW_INIT is defined, then the function
2571 fdc_hw_init() is called at the beginning of the FDC
2572 setup. fdc_hw_init() must be provided by the board
2573 source code. It is used to make hardware dependant
2574 initializations.
2575
2576 - CONFIG_SYS_IMMR: Physical address of the Internal Memory.
2577 DO NOT CHANGE unless you know exactly what you're
2578 doing! (11-4) [MPC8xx/82xx systems only]
2579
2580 - CONFIG_SYS_INIT_RAM_ADDR:
2581
2582 Start address of memory area that can be used for
2583 initial data and stack; please note that this must be
2584 writable memory that is working WITHOUT special
2585 initialization, i. e. you CANNOT use normal RAM which
2586 will become available only after programming the
2587 memory controller and running certain initialization
2588 sequences.
2589
2590 U-Boot uses the following memory types:
2591 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
2592 - MPC824X: data cache
2593 - PPC4xx: data cache
2594
2595 - CONFIG_SYS_GBL_DATA_OFFSET:
2596
2597 Offset of the initial data structure in the memory
2598 area defined by CONFIG_SYS_INIT_RAM_ADDR. Usually
2599 CONFIG_SYS_GBL_DATA_OFFSET is chosen such that the initial
2600 data is located at the end of the available space
2601 (sometimes written as (CONFIG_SYS_INIT_RAM_END -
2602 CONFIG_SYS_INIT_DATA_SIZE), and the initial stack is just
2603 below that area (growing from (CONFIG_SYS_INIT_RAM_ADDR +
2604 CONFIG_SYS_GBL_DATA_OFFSET) downward.
2605
2606 Note:
2607 On the MPC824X (or other systems that use the data
2608 cache for initial memory) the address chosen for
2609 CONFIG_SYS_INIT_RAM_ADDR is basically arbitrary - it must
2610 point to an otherwise UNUSED address space between
2611 the top of RAM and the start of the PCI space.
2612
2613 - CONFIG_SYS_SIUMCR: SIU Module Configuration (11-6)
2614
2615 - CONFIG_SYS_SYPCR: System Protection Control (11-9)
2616
2617 - CONFIG_SYS_TBSCR: Time Base Status and Control (11-26)
2618
2619 - CONFIG_SYS_PISCR: Periodic Interrupt Status and Control (11-31)
2620
2621 - CONFIG_SYS_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
2622
2623 - CONFIG_SYS_SCCR: System Clock and reset Control Register (15-27)
2624
2625 - CONFIG_SYS_OR_TIMING_SDRAM:
2626 SDRAM timing
2627
2628 - CONFIG_SYS_MAMR_PTA:
2629 periodic timer for refresh
2630
2631 - CONFIG_SYS_DER: Debug Event Register (37-47)
2632
2633 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CONFIG_SYS_REMAP_OR_AM,
2634 CONFIG_SYS_PRELIM_OR_AM, CONFIG_SYS_OR_TIMING_FLASH, CONFIG_SYS_OR0_REMAP,
2635 CONFIG_SYS_OR0_PRELIM, CONFIG_SYS_BR0_PRELIM, CONFIG_SYS_OR1_REMAP, CONFIG_SYS_OR1_PRELIM,
2636 CONFIG_SYS_BR1_PRELIM:
2637 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
2638
2639 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
2640 CONFIG_SYS_OR_TIMING_SDRAM, CONFIG_SYS_OR2_PRELIM, CONFIG_SYS_BR2_PRELIM,
2641 CONFIG_SYS_OR3_PRELIM, CONFIG_SYS_BR3_PRELIM:
2642 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
2643
2644 - CONFIG_SYS_MAMR_PTA, CONFIG_SYS_MPTPR_2BK_4K, CONFIG_SYS_MPTPR_1BK_4K, CONFIG_SYS_MPTPR_2BK_8K,
2645 CONFIG_SYS_MPTPR_1BK_8K, CONFIG_SYS_MAMR_8COL, CONFIG_SYS_MAMR_9COL:
2646 Machine Mode Register and Memory Periodic Timer
2647 Prescaler definitions (SDRAM timing)
2648
2649 - CONFIG_SYS_I2C_UCODE_PATCH, CONFIG_SYS_I2C_DPMEM_OFFSET [0x1FC0]:
2650 enable I2C microcode relocation patch (MPC8xx);
2651 define relocation offset in DPRAM [DSP2]
2652
2653 - CONFIG_SYS_SMC_UCODE_PATCH, CONFIG_SYS_SMC_DPMEM_OFFSET [0x1FC0]:
2654 enable SMC microcode relocation patch (MPC8xx);
2655 define relocation offset in DPRAM [SMC1]
2656
2657 - CONFIG_SYS_SPI_UCODE_PATCH, CONFIG_SYS_SPI_DPMEM_OFFSET [0x1FC0]:
2658 enable SPI microcode relocation patch (MPC8xx);
2659 define relocation offset in DPRAM [SCC4]
2660
2661 - CONFIG_SYS_USE_OSCCLK:
2662 Use OSCM clock mode on MBX8xx board. Be careful,
2663 wrong setting might damage your board. Read
2664 doc/README.MBX before setting this variable!
2665
2666 - CONFIG_SYS_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
2667 Offset of the bootmode word in DPRAM used by post
2668 (Power On Self Tests). This definition overrides
2669 #define'd default value in commproc.h resp.
2670 cpm_8260.h.
2671
2672 - CONFIG_SYS_PCI_SLV_MEM_LOCAL, CONFIG_SYS_PCI_SLV_MEM_BUS, CONFIG_SYS_PICMR0_MASK_ATTRIB,
2673 CONFIG_SYS_PCI_MSTR0_LOCAL, CONFIG_SYS_PCIMSK0_MASK, CONFIG_SYS_PCI_MSTR1_LOCAL,
2674 CONFIG_SYS_PCIMSK1_MASK, CONFIG_SYS_PCI_MSTR_MEM_LOCAL, CONFIG_SYS_PCI_MSTR_MEM_BUS,
2675 CONFIG_SYS_CPU_PCI_MEM_START, CONFIG_SYS_PCI_MSTR_MEM_SIZE, CONFIG_SYS_POCMR0_MASK_ATTRIB,
2676 CONFIG_SYS_PCI_MSTR_MEMIO_LOCAL, CONFIG_SYS_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
2677 CONFIG_SYS_PCI_MSTR_MEMIO_SIZE, CONFIG_SYS_POCMR1_MASK_ATTRIB, CONFIG_SYS_PCI_MSTR_IO_LOCAL,
2678 CONFIG_SYS_PCI_MSTR_IO_BUS, CONFIG_SYS_CPU_PCI_IO_START, CONFIG_SYS_PCI_MSTR_IO_SIZE,
2679 CONFIG_SYS_POCMR2_MASK_ATTRIB: (MPC826x only)
2680 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
2681
2682 - CONFIG_PCI_DISABLE_PCIE:
2683 Disable PCI-Express on systems where it is supported but not
2684 required.
2685
2686 - CONFIG_SPD_EEPROM
2687 Get DDR timing information from an I2C EEPROM. Common
2688 with pluggable memory modules such as SODIMMs
2689
2690 SPD_EEPROM_ADDRESS
2691 I2C address of the SPD EEPROM
2692
2693 - CONFIG_SYS_SPD_BUS_NUM
2694 If SPD EEPROM is on an I2C bus other than the first
2695 one, specify here. Note that the value must resolve
2696 to something your driver can deal with.
2697
2698 - CONFIG_SYS_83XX_DDR_USES_CS0
2699 Only for 83xx systems. If specified, then DDR should
2700 be configured using CS0 and CS1 instead of CS2 and CS3.
2701
2702 - CONFIG_ETHER_ON_FEC[12]
2703 Define to enable FEC[12] on a 8xx series processor.
2704
2705 - CONFIG_FEC[12]_PHY
2706 Define to the hardcoded PHY address which corresponds
2707 to the given FEC; i. e.
2708 #define CONFIG_FEC1_PHY 4
2709 means that the PHY with address 4 is connected to FEC1
2710
2711 When set to -1, means to probe for first available.
2712
2713 - CONFIG_FEC[12]_PHY_NORXERR
2714 The PHY does not have a RXERR line (RMII only).
2715 (so program the FEC to ignore it).
2716
2717 - CONFIG_RMII
2718 Enable RMII mode for all FECs.
2719 Note that this is a global option, we can't
2720 have one FEC in standard MII mode and another in RMII mode.
2721
2722 - CONFIG_CRC32_VERIFY
2723 Add a verify option to the crc32 command.
2724 The syntax is:
2725
2726 => crc32 -v <address> <count> <crc32>
2727
2728 Where address/count indicate a memory area
2729 and crc32 is the correct crc32 which the
2730 area should have.
2731
2732 - CONFIG_LOOPW
2733 Add the "loopw" memory command. This only takes effect if
2734 the memory commands are activated globally (CONFIG_CMD_MEM).
2735
2736 - CONFIG_MX_CYCLIC
2737 Add the "mdc" and "mwc" memory commands. These are cyclic
2738 "md/mw" commands.
2739 Examples:
2740
2741 => mdc.b 10 4 500
2742 This command will print 4 bytes (10,11,12,13) each 500 ms.
2743
2744 => mwc.l 100 12345678 10
2745 This command will write 12345678 to address 100 all 10 ms.
2746
2747 This only takes effect if the memory commands are activated
2748 globally (CONFIG_CMD_MEM).
2749
2750 - CONFIG_SKIP_LOWLEVEL_INIT
2751 - CONFIG_SKIP_RELOCATE_UBOOT
2752
2753 [ARM only] If these variables are defined, then
2754 certain low level initializations (like setting up
2755 the memory controller) are omitted and/or U-Boot does
2756 not relocate itself into RAM.
2757 Normally these variables MUST NOT be defined. The
2758 only exception is when U-Boot is loaded (to RAM) by
2759 some other boot loader or by a debugger which
2760 performs these initializations itself.
2761
2762 - CONFIG_PRELOADER
2763
2764 Modifies the behaviour of start.S when compiling a loader
2765 that is executed before the actual U-Boot. E.g. when
2766 compiling a NAND SPL.
2767
2768 Building the Software:
2769 ======================
2770
2771 Building U-Boot has been tested in several native build environments
2772 and in many different cross environments. Of course we cannot support
2773 all possibly existing versions of cross development tools in all
2774 (potentially obsolete) versions. In case of tool chain problems we
2775 recommend to use the ELDK (see http://www.denx.de/wiki/DULG/ELDK)
2776 which is extensively used to build and test U-Boot.
2777
2778 If you are not using a native environment, it is assumed that you
2779 have GNU cross compiling tools available in your path. In this case,
2780 you must set the environment variable CROSS_COMPILE in your shell.
2781 Note that no changes to the Makefile or any other source files are
2782 necessary. For example using the ELDK on a 4xx CPU, please enter:
2783
2784 $ CROSS_COMPILE=ppc_4xx-
2785 $ export CROSS_COMPILE
2786
2787 Note: If you wish to generate Windows versions of the utilities in
2788 the tools directory you can use the MinGW toolchain
2789 (http://www.mingw.org). Set your HOST tools to the MinGW
2790 toolchain and execute 'make tools'. For example:
2791
2792 $ make HOSTCC=i586-mingw32msvc-gcc HOSTSTRIP=i586-mingw32msvc-strip tools
2793
2794 Binaries such as tools/mkimage.exe will be created which can
2795 be executed on computers running Windows.
2796
2797 U-Boot is intended to be simple to build. After installing the
2798 sources you must configure U-Boot for one specific board type. This
2799 is done by typing:
2800
2801 make NAME_config
2802
2803 where "NAME_config" is the name of one of the existing configu-
2804 rations; see the main Makefile for supported names.
2805
2806 Note: for some board special configuration names may exist; check if
2807 additional information is available from the board vendor; for
2808 instance, the TQM823L systems are available without (standard)
2809 or with LCD support. You can select such additional "features"
2810 when choosing the configuration, i. e.
2811
2812 make TQM823L_config
2813 - will configure for a plain TQM823L, i. e. no LCD support
2814
2815 make TQM823L_LCD_config
2816 - will configure for a TQM823L with U-Boot console on LCD
2817
2818 etc.
2819
2820
2821 Finally, type "make all", and you should get some working U-Boot
2822 images ready for download to / installation on your system:
2823
2824 - "u-boot.bin" is a raw binary image
2825 - "u-boot" is an image in ELF binary format
2826 - "u-boot.srec" is in Motorola S-Record format
2827
2828 By default the build is performed locally and the objects are saved
2829 in the source directory. One of the two methods can be used to change
2830 this behavior and build U-Boot to some external directory:
2831
2832 1. Add O= to the make command line invocations:
2833
2834 make O=/tmp/build distclean
2835 make O=/tmp/build NAME_config
2836 make O=/tmp/build all
2837
2838 2. Set environment variable BUILD_DIR to point to the desired location:
2839
2840 export BUILD_DIR=/tmp/build
2841 make distclean
2842 make NAME_config
2843 make all
2844
2845 Note that the command line "O=" setting overrides the BUILD_DIR environment
2846 variable.
2847
2848
2849 Please be aware that the Makefiles assume you are using GNU make, so
2850 for instance on NetBSD you might need to use "gmake" instead of
2851 native "make".
2852
2853
2854 If the system board that you have is not listed, then you will need
2855 to port U-Boot to your hardware platform. To do this, follow these
2856 steps:
2857
2858 1. Add a new configuration option for your board to the toplevel
2859 "Makefile" and to the "MAKEALL" script, using the existing
2860 entries as examples. Note that here and at many other places
2861 boards and other names are listed in alphabetical sort order. Please
2862 keep this order.
2863 2. Create a new directory to hold your board specific code. Add any
2864 files you need. In your board directory, you will need at least
2865 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2866 3. Create a new configuration file "include/configs/<board>.h" for
2867 your board
2868 3. If you're porting U-Boot to a new CPU, then also create a new
2869 directory to hold your CPU specific code. Add any files you need.
2870 4. Run "make <board>_config" with your new name.
2871 5. Type "make", and you should get a working "u-boot.srec" file
2872 to be installed on your target system.
2873 6. Debug and solve any problems that might arise.
2874 [Of course, this last step is much harder than it sounds.]
2875
2876
2877 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2878 ==============================================================
2879
2880 If you have modified U-Boot sources (for instance added a new board
2881 or support for new devices, a new CPU, etc.) you are expected to
2882 provide feedback to the other developers. The feedback normally takes
2883 the form of a "patch", i. e. a context diff against a certain (latest
2884 official or latest in the git repository) version of U-Boot sources.
2885
2886 But before you submit such a patch, please verify that your modifi-
2887 cation did not break existing code. At least make sure that *ALL* of
2888 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2889 just run the "MAKEALL" script, which will configure and build U-Boot
2890 for ALL supported system. Be warned, this will take a while. You can
2891 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2892 environment variable to the script, i. e. to use the ELDK cross tools
2893 you can type
2894
2895 CROSS_COMPILE=ppc_8xx- MAKEALL
2896
2897 or to build on a native PowerPC system you can type
2898
2899 CROSS_COMPILE=' ' MAKEALL
2900
2901 When using the MAKEALL script, the default behaviour is to build
2902 U-Boot in the source directory. This location can be changed by
2903 setting the BUILD_DIR environment variable. Also, for each target
2904 built, the MAKEALL script saves two log files (<target>.ERR and
2905 <target>.MAKEALL) in the <source dir>/LOG directory. This default
2906 location can be changed by setting the MAKEALL_LOGDIR environment
2907 variable. For example:
2908
2909 export BUILD_DIR=/tmp/build
2910 export MAKEALL_LOGDIR=/tmp/log
2911 CROSS_COMPILE=ppc_8xx- MAKEALL
2912
2913 With the above settings build objects are saved in the /tmp/build,
2914 log files are saved in the /tmp/log and the source tree remains clean
2915 during the whole build process.
2916
2917
2918 See also "U-Boot Porting Guide" below.
2919
2920
2921 Monitor Commands - Overview:
2922 ============================
2923
2924 go - start application at address 'addr'
2925 run - run commands in an environment variable
2926 bootm - boot application image from memory
2927 bootp - boot image via network using BootP/TFTP protocol
2928 tftpboot- boot image via network using TFTP protocol
2929 and env variables "ipaddr" and "serverip"
2930 (and eventually "gatewayip")
2931 rarpboot- boot image via network using RARP/TFTP protocol
2932 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2933 loads - load S-Record file over serial line
2934 loadb - load binary file over serial line (kermit mode)
2935 md - memory display
2936 mm - memory modify (auto-incrementing)
2937 nm - memory modify (constant address)
2938 mw - memory write (fill)
2939 cp - memory copy
2940 cmp - memory compare
2941 crc32 - checksum calculation
2942 i2c - I2C sub-system
2943 sspi - SPI utility commands
2944 base - print or set address offset
2945 printenv- print environment variables
2946 setenv - set environment variables
2947 saveenv - save environment variables to persistent storage
2948 protect - enable or disable FLASH write protection
2949 erase - erase FLASH memory
2950 flinfo - print FLASH memory information
2951 bdinfo - print Board Info structure
2952 iminfo - print header information for application image
2953 coninfo - print console devices and informations
2954 ide - IDE sub-system
2955 loop - infinite loop on address range
2956 loopw - infinite write loop on address range
2957 mtest - simple RAM test
2958 icache - enable or disable instruction cache
2959 dcache - enable or disable data cache
2960 reset - Perform RESET of the CPU
2961 echo - echo args to console
2962 version - print monitor version
2963 help - print online help
2964 ? - alias for 'help'
2965
2966
2967 Monitor Commands - Detailed Description:
2968 ========================================
2969
2970 TODO.
2971
2972 For now: just type "help <command>".
2973
2974
2975 Environment Variables:
2976 ======================
2977
2978 U-Boot supports user configuration using Environment Variables which
2979 can be made persistent by saving to Flash memory.
2980
2981 Environment Variables are set using "setenv", printed using
2982 "printenv", and saved to Flash using "saveenv". Using "setenv"
2983 without a value can be used to delete a variable from the
2984 environment. As long as you don't save the environment you are
2985 working with an in-memory copy. In case the Flash area containing the
2986 environment is erased by accident, a default environment is provided.
2987
2988 Some configuration options can be set using Environment Variables:
2989
2990 baudrate - see CONFIG_BAUDRATE
2991
2992 bootdelay - see CONFIG_BOOTDELAY
2993
2994 bootcmd - see CONFIG_BOOTCOMMAND
2995
2996 bootargs - Boot arguments when booting an RTOS image
2997
2998 bootfile - Name of the image to load with TFTP
2999
3000 bootm_low - Memory range available for image processing in the bootm
3001 command can be restricted. This variable is given as
3002 a hexadecimal number and defines lowest address allowed
3003 for use by the bootm command. See also "bootm_size"
3004 environment variable. Address defined by "bootm_low" is
3005 also the base of the initial memory mapping for the Linux
3006 kernel -- see the description of CONFIG_SYS_BOOTMAPSZ.
3007
3008 bootm_size - Memory range available for image processing in the bootm
3009 command can be restricted. This variable is given as
3010 a hexadecimal number and defines the size of the region
3011 allowed for use by the bootm command. See also "bootm_low"
3012 environment variable.
3013
3014 updatefile - Location of the software update file on a TFTP server, used
3015 by the automatic software update feature. Please refer to
3016 documentation in doc/README.update for more details.
3017
3018 autoload - if set to "no" (any string beginning with 'n'),
3019 "bootp" will just load perform a lookup of the
3020 configuration from the BOOTP server, but not try to
3021 load any image using TFTP
3022
3023 autostart - if set to "yes", an image loaded using the "bootp",
3024 "rarpboot", "tftpboot" or "diskboot" commands will
3025 be automatically started (by internally calling
3026 "bootm")
3027
3028 If set to "no", a standalone image passed to the
3029 "bootm" command will be copied to the load address
3030 (and eventually uncompressed), but NOT be started.
3031 This can be used to load and uncompress arbitrary
3032 data.
3033
3034 i2cfast - (PPC405GP|PPC405EP only)
3035 if set to 'y' configures Linux I2C driver for fast
3036 mode (400kHZ). This environment variable is used in
3037 initialization code. So, for changes to be effective
3038 it must be saved and board must be reset.
3039
3040 initrd_high - restrict positioning of initrd images:
3041 If this variable is not set, initrd images will be
3042 copied to the highest possible address in RAM; this
3043 is usually what you want since it allows for
3044 maximum initrd size. If for some reason you want to
3045 make sure that the initrd image is loaded below the
3046 CONFIG_SYS_BOOTMAPSZ limit, you can set this environment
3047 variable to a value of "no" or "off" or "0".
3048 Alternatively, you can set it to a maximum upper
3049 address to use (U-Boot will still check that it
3050 does not overwrite the U-Boot stack and data).
3051
3052 For instance, when you have a system with 16 MB
3053 RAM, and want to reserve 4 MB from use by Linux,
3054 you can do this by adding "mem=12M" to the value of
3055 the "bootargs" variable. However, now you must make
3056 sure that the initrd image is placed in the first
3057 12 MB as well - this can be done with
3058
3059 setenv initrd_high 00c00000
3060
3061 If you set initrd_high to 0xFFFFFFFF, this is an
3062 indication to U-Boot that all addresses are legal
3063 for the Linux kernel, including addresses in flash
3064 memory. In this case U-Boot will NOT COPY the
3065 ramdisk at all. This may be useful to reduce the
3066 boot time on your system, but requires that this
3067 feature is supported by your Linux kernel.
3068
3069 ipaddr - IP address; needed for tftpboot command
3070
3071 loadaddr - Default load address for commands like "bootp",
3072 "rarpboot", "tftpboot", "loadb" or "diskboot"
3073
3074 loads_echo - see CONFIG_LOADS_ECHO
3075
3076 serverip - TFTP server IP address; needed for tftpboot command
3077
3078 bootretry - see CONFIG_BOOT_RETRY_TIME
3079
3080 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
3081
3082 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
3083
3084 ethprime - When CONFIG_NET_MULTI is enabled controls which
3085 interface is used first.
3086
3087 ethact - When CONFIG_NET_MULTI is enabled controls which
3088 interface is currently active. For example you
3089 can do the following
3090
3091 => setenv ethact FEC ETHERNET
3092 => ping 192.168.0.1 # traffic sent on FEC ETHERNET
3093 => setenv ethact SCC ETHERNET
3094 => ping 10.0.0.1 # traffic sent on SCC ETHERNET
3095
3096 ethrotate - When set to "no" U-Boot does not go through all
3097 available network interfaces.
3098 It just stays at the currently selected interface.
3099
3100 netretry - When set to "no" each network operation will
3101 either succeed or fail without retrying.
3102 When set to "once" the network operation will
3103 fail when all the available network interfaces
3104 are tried once without success.
3105 Useful on scripts which control the retry operation
3106 themselves.
3107
3108 npe_ucode - set load address for the NPE microcode
3109
3110 tftpsrcport - If this is set, the value is used for TFTP's
3111 UDP source port.
3112
3113 tftpdstport - If this is set, the value is used for TFTP's UDP
3114 destination port instead of the Well Know Port 69.
3115
3116 vlan - When set to a value < 4095 the traffic over
3117 Ethernet is encapsulated/received over 802.1q
3118 VLAN tagged frames.
3119
3120 The following environment variables may be used and automatically
3121 updated by the network boot commands ("bootp" and "rarpboot"),
3122 depending the information provided by your boot server:
3123
3124 bootfile - see above
3125 dnsip - IP address of your Domain Name Server
3126 dnsip2 - IP address of your secondary Domain Name Server
3127 gatewayip - IP address of the Gateway (Router) to use
3128 hostname - Target hostname
3129 ipaddr - see above
3130 netmask - Subnet Mask
3131 rootpath - Pathname of the root filesystem on the NFS server
3132 serverip - see above
3133
3134
3135 There are two special Environment Variables:
3136
3137 serial# - contains hardware identification information such
3138 as type string and/or serial number
3139 ethaddr - Ethernet address
3140
3141 These variables can be set only once (usually during manufacturing of
3142 the board). U-Boot refuses to delete or overwrite these variables
3143 once they have been set once.
3144
3145
3146 Further special Environment Variables:
3147
3148 ver - Contains the U-Boot version string as printed
3149 with the "version" command. This variable is
3150 readonly (see CONFIG_VERSION_VARIABLE).
3151
3152
3153 Please note that changes to some configuration parameters may take
3154 only effect after the next boot (yes, that's just like Windoze :-).
3155
3156
3157 Command Line Parsing:
3158 =====================
3159
3160 There are two different command line parsers available with U-Boot:
3161 the old "simple" one, and the much more powerful "hush" shell:
3162
3163 Old, simple command line parser:
3164 --------------------------------
3165
3166 - supports environment variables (through setenv / saveenv commands)
3167 - several commands on one line, separated by ';'
3168 - variable substitution using "... ${name} ..." syntax
3169 - special characters ('$', ';') can be escaped by prefixing with '\',
3170 for example:
3171 setenv bootcmd bootm \${address}
3172 - You can also escape text by enclosing in single apostrophes, for example:
3173 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
3174
3175 Hush shell:
3176 -----------
3177
3178 - similar to Bourne shell, with control structures like
3179 if...then...else...fi, for...do...done; while...do...done,
3180 until...do...done, ...
3181 - supports environment ("global") variables (through setenv / saveenv
3182 commands) and local shell variables (through standard shell syntax
3183 "name=value"); only environment variables can be used with "run"
3184 command
3185
3186 General rules:
3187 --------------
3188
3189 (1) If a command line (or an environment variable executed by a "run"
3190 command) contains several commands separated by semicolon, and
3191 one of these commands fails, then the remaining commands will be
3192 executed anyway.
3193
3194 (2) If you execute several variables with one call to run (i. e.
3195 calling run with a list of variables as arguments), any failing
3196 command will cause "run" to terminate, i. e. the remaining
3197 variables are not executed.
3198
3199 Note for Redundant Ethernet Interfaces:
3200 =======================================
3201
3202 Some boards come with redundant Ethernet interfaces; U-Boot supports
3203 such configurations and is capable of automatic selection of a
3204 "working" interface when needed. MAC assignment works as follows:
3205
3206 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
3207 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
3208 "eth1addr" (=>eth1), "eth2addr", ...
3209
3210 If the network interface stores some valid MAC address (for instance
3211 in SROM), this is used as default address if there is NO correspon-
3212 ding setting in the environment; if the corresponding environment
3213 variable is set, this overrides the settings in the card; that means:
3214
3215 o If the SROM has a valid MAC address, and there is no address in the
3216 environment, the SROM's address is used.
3217
3218 o If there is no valid address in the SROM, and a definition in the
3219 environment exists, then the value from the environment variable is
3220 used.
3221
3222 o If both the SROM and the environment contain a MAC address, and
3223 both addresses are the same, this MAC address is used.
3224
3225 o If both the SROM and the environment contain a MAC address, and the
3226 addresses differ, the value from the environment is used and a
3227 warning is printed.
3228
3229 o If neither SROM nor the environment contain a MAC address, an error
3230 is raised.
3231
3232
3233 Image Formats:
3234 ==============
3235
3236 U-Boot is capable of booting (and performing other auxiliary operations on)
3237 images in two formats:
3238
3239 New uImage format (FIT)
3240 -----------------------
3241
3242 Flexible and powerful format based on Flattened Image Tree -- FIT (similar
3243 to Flattened Device Tree). It allows the use of images with multiple
3244 components (several kernels, ramdisks, etc.), with contents protected by
3245 SHA1, MD5 or CRC32. More details are found in the doc/uImage.FIT directory.
3246
3247
3248 Old uImage format
3249 -----------------
3250
3251 Old image format is based on binary files which can be basically anything,
3252 preceded by a special header; see the definitions in include/image.h for
3253 details; basically, the header defines the following image properties:
3254
3255 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
3256 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
3257 LynxOS, pSOS, QNX, RTEMS, INTEGRITY;
3258 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, LynxOS,
3259 INTEGRITY).
3260 * Target CPU Architecture (Provisions for Alpha, ARM, AVR32, Intel x86,
3261 IA64, MIPS, NIOS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
3262 Currently supported: ARM, AVR32, Intel x86, MIPS, NIOS, PowerPC).
3263 * Compression Type (uncompressed, gzip, bzip2)
3264 * Load Address
3265 * Entry Point
3266 * Image Name
3267 * Image Timestamp
3268
3269 The header is marked by a special Magic Number, and both the header
3270 and the data portions of the image are secured against corruption by
3271 CRC32 checksums.
3272
3273
3274 Linux Support:
3275 ==============
3276
3277 Although U-Boot should support any OS or standalone application
3278 easily, the main focus has always been on Linux during the design of
3279 U-Boot.
3280
3281 U-Boot includes many features that so far have been part of some
3282 special "boot loader" code within the Linux kernel. Also, any
3283 "initrd" images to be used are no longer part of one big Linux image;
3284 instead, kernel and "initrd" are separate images. This implementation
3285 serves several purposes:
3286
3287 - the same features can be used for other OS or standalone
3288 applications (for instance: using compressed images to reduce the
3289 Flash memory footprint)
3290
3291 - it becomes much easier to port new Linux kernel versions because
3292 lots of low-level, hardware dependent stuff are done by U-Boot
3293
3294 - the same Linux kernel image can now be used with different "initrd"
3295 images; of course this also means that different kernel images can
3296 be run with the same "initrd". This makes testing easier (you don't
3297 have to build a new "zImage.initrd" Linux image when you just
3298 change a file in your "initrd"). Also, a field-upgrade of the
3299 software is easier now.
3300
3301
3302 Linux HOWTO:
3303 ============
3304
3305 Porting Linux to U-Boot based systems:
3306 ---------------------------------------
3307
3308 U-Boot cannot save you from doing all the necessary modifications to
3309 configure the Linux device drivers for use with your target hardware
3310 (no, we don't intend to provide a full virtual machine interface to
3311 Linux :-).
3312
3313 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
3314
3315 Just make sure your machine specific header file (for instance
3316 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
3317 Information structure as we define in include/asm-<arch>/u-boot.h,
3318 and make sure that your definition of IMAP_ADDR uses the same value
3319 as your U-Boot configuration in CONFIG_SYS_IMMR.
3320
3321
3322 Configuring the Linux kernel:
3323 -----------------------------
3324
3325 No specific requirements for U-Boot. Make sure you have some root
3326 device (initial ramdisk, NFS) for your target system.
3327
3328
3329 Building a Linux Image:
3330 -----------------------
3331
3332 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
3333 not used. If you use recent kernel source, a new build target
3334 "uImage" will exist which automatically builds an image usable by
3335 U-Boot. Most older kernels also have support for a "pImage" target,
3336 which was introduced for our predecessor project PPCBoot and uses a
3337 100% compatible format.
3338
3339 Example:
3340
3341 make TQM850L_config
3342 make oldconfig
3343 make dep
3344 make uImage
3345
3346 The "uImage" build target uses a special tool (in 'tools/mkimage') to
3347 encapsulate a compressed Linux kernel image with header information,
3348 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
3349
3350 * build a standard "vmlinux" kernel image (in ELF binary format):
3351
3352 * convert the kernel into a raw binary image:
3353
3354 ${CROSS_COMPILE}-objcopy -O binary \
3355 -R .note -R .comment \
3356 -S vmlinux linux.bin
3357
3358 * compress the binary image:
3359
3360 gzip -9 linux.bin
3361
3362 * package compressed binary image for U-Boot:
3363
3364 mkimage -A ppc -O linux -T kernel -C gzip \
3365 -a 0 -e 0 -n "Linux Kernel Image" \
3366 -d linux.bin.gz uImage
3367
3368
3369 The "mkimage" tool can also be used to create ramdisk images for use
3370 with U-Boot, either separated from the Linux kernel image, or
3371 combined into one file. "mkimage" encapsulates the images with a 64
3372 byte header containing information about target architecture,
3373 operating system, image type, compression method, entry points, time
3374 stamp, CRC32 checksums, etc.
3375
3376 "mkimage" can be called in two ways: to verify existing images and
3377 print the header information, or to build new images.
3378
3379 In the first form (with "-l" option) mkimage lists the information
3380 contained in the header of an existing U-Boot image; this includes
3381 checksum verification:
3382
3383 tools/mkimage -l image
3384 -l ==> list image header information
3385
3386 The second form (with "-d" option) is used to build a U-Boot image
3387 from a "data file" which is used as image payload:
3388
3389 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
3390 -n name -d data_file image
3391 -A ==> set architecture to 'arch'
3392 -O ==> set operating system to 'os'
3393 -T ==> set image type to 'type'
3394 -C ==> set compression type 'comp'
3395 -a ==> set load address to 'addr' (hex)
3396 -e ==> set entry point to 'ep' (hex)
3397 -n ==> set image name to 'name'
3398 -d ==> use image data from 'datafile'
3399
3400 Right now, all Linux kernels for PowerPC systems use the same load
3401 address (0x00000000), but the entry point address depends on the
3402 kernel version:
3403
3404 - 2.2.x kernels have the entry point at 0x0000000C,
3405 - 2.3.x and later kernels have the entry point at 0x00000000.
3406
3407 So a typical call to build a U-Boot image would read:
3408
3409 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3410 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
3411 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
3412 > examples/uImage.TQM850L
3413 Image Name: 2.4.4 kernel for TQM850L
3414 Created: Wed Jul 19 02:34:59 2000
3415 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3416 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3417 Load Address: 0x00000000
3418 Entry Point: 0x00000000
3419
3420 To verify the contents of the image (or check for corruption):
3421
3422 -> tools/mkimage -l examples/uImage.TQM850L
3423 Image Name: 2.4.4 kernel for TQM850L
3424 Created: Wed Jul 19 02:34:59 2000
3425 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3426 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
3427 Load Address: 0x00000000
3428 Entry Point: 0x00000000
3429
3430 NOTE: for embedded systems where boot time is critical you can trade
3431 speed for memory and install an UNCOMPRESSED image instead: this
3432 needs more space in Flash, but boots much faster since it does not
3433 need to be uncompressed:
3434
3435 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
3436 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
3437 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
3438 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
3439 > examples/uImage.TQM850L-uncompressed
3440 Image Name: 2.4.4 kernel for TQM850L
3441 Created: Wed Jul 19 02:34:59 2000
3442 Image Type: PowerPC Linux Kernel Image (uncompressed)
3443 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
3444 Load Address: 0x00000000
3445 Entry Point: 0x00000000
3446
3447
3448 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
3449 when your kernel is intended to use an initial ramdisk:
3450
3451 -> tools/mkimage -n 'Simple Ramdisk Image' \
3452 > -A ppc -O linux -T ramdisk -C gzip \
3453 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
3454 Image Name: Simple Ramdisk Image
3455 Created: Wed Jan 12 14:01:50 2000
3456 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3457 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
3458 Load Address: 0x00000000
3459 Entry Point: 0x00000000
3460
3461
3462 Installing a Linux Image:
3463 -------------------------
3464
3465 To downloading a U-Boot image over the serial (console) interface,
3466 you must convert the image to S-Record format:
3467
3468 objcopy -I binary -O srec examples/image examples/image.srec
3469
3470 The 'objcopy' does not understand the information in the U-Boot
3471 image header, so the resulting S-Record file will be relative to
3472 address 0x00000000. To load it to a given address, you need to
3473 specify the target address as 'offset' parameter with the 'loads'
3474 command.
3475
3476 Example: install the image to address 0x40100000 (which on the
3477 TQM8xxL is in the first Flash bank):
3478
3479 => erase 40100000 401FFFFF
3480
3481 .......... done
3482 Erased 8 sectors
3483
3484 => loads 40100000
3485 ## Ready for S-Record download ...
3486 ~>examples/image.srec
3487 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
3488 ...
3489 15989 15990 15991 15992
3490 [file transfer complete]
3491 [connected]
3492 ## Start Addr = 0x00000000
3493
3494
3495 You can check the success of the download using the 'iminfo' command;
3496 this includes a checksum verification so you can be sure no data
3497 corruption happened:
3498
3499 => imi 40100000
3500
3501 ## Checking Image at 40100000 ...
3502 Image Name: 2.2.13 for initrd on TQM850L
3503 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3504 Data Size: 335725 Bytes = 327 kB = 0 MB
3505 Load Address: 00000000
3506 Entry Point: 0000000c
3507 Verifying Checksum ... OK
3508
3509
3510 Boot Linux:
3511 -----------
3512
3513 The "bootm" command is used to boot an application that is stored in
3514 memory (RAM or Flash). In case of a Linux kernel image, the contents
3515 of the "bootargs" environment variable is passed to the kernel as
3516 parameters. You can check and modify this variable using the
3517 "printenv" and "setenv" commands:
3518
3519
3520 => printenv bootargs
3521 bootargs=root=/dev/ram
3522
3523 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3524
3525 => printenv bootargs
3526 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3527
3528 => bootm 40020000
3529 ## Booting Linux kernel at 40020000 ...
3530 Image Name: 2.2.13 for NFS on TQM850L
3531 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3532 Data Size: 381681 Bytes = 372 kB = 0 MB
3533 Load Address: 00000000
3534 Entry Point: 0000000c
3535 Verifying Checksum ... OK
3536 Uncompressing Kernel Image ... OK
3537 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
3538 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
3539 time_init: decrementer frequency = 187500000/60
3540 Calibrating delay loop... 49.77 BogoMIPS
3541 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
3542 ...
3543
3544 If you want to boot a Linux kernel with initial RAM disk, you pass
3545 the memory addresses of both the kernel and the initrd image (PPBCOOT
3546 format!) to the "bootm" command:
3547
3548 => imi 40100000 40200000
3549
3550 ## Checking Image at 40100000 ...
3551 Image Name: 2.2.13 for initrd on TQM850L
3552 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3553 Data Size: 335725 Bytes = 327 kB = 0 MB
3554 Load Address: 00000000
3555 Entry Point: 0000000c
3556 Verifying Checksum ... OK
3557
3558 ## Checking Image at 40200000 ...
3559 Image Name: Simple Ramdisk Image
3560 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3561 Data Size: 566530 Bytes = 553 kB = 0 MB
3562 Load Address: 00000000
3563 Entry Point: 00000000
3564 Verifying Checksum ... OK
3565
3566 => bootm 40100000 40200000
3567 ## Booting Linux kernel at 40100000 ...
3568 Image Name: 2.2.13 for initrd on TQM850L
3569 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3570 Data Size: 335725 Bytes = 327 kB = 0 MB
3571 Load Address: 00000000
3572 Entry Point: 0000000c
3573 Verifying Checksum ... OK
3574 Uncompressing Kernel Image ... OK
3575 ## Loading RAMDisk Image at 40200000 ...
3576 Image Name: Simple Ramdisk Image
3577 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
3578 Data Size: 566530 Bytes = 553 kB = 0 MB
3579 Load Address: 00000000
3580 Entry Point: 00000000
3581 Verifying Checksum ... OK
3582 Loading Ramdisk ... OK
3583 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
3584 Boot arguments: root=/dev/ram
3585 time_init: decrementer frequency = 187500000/60
3586 Calibrating delay loop... 49.77 BogoMIPS
3587 ...
3588 RAMDISK: Compressed image found at block 0
3589 VFS: Mounted root (ext2 filesystem).
3590
3591 bash#
3592
3593 Boot Linux and pass a flat device tree:
3594 -----------
3595
3596 First, U-Boot must be compiled with the appropriate defines. See the section
3597 titled "Linux Kernel Interface" above for a more in depth explanation. The
3598 following is an example of how to start a kernel and pass an updated
3599 flat device tree:
3600
3601 => print oftaddr
3602 oftaddr=0x300000
3603 => print oft
3604 oft=oftrees/mpc8540ads.dtb
3605 => tftp $oftaddr $oft
3606 Speed: 1000, full duplex
3607 Using TSEC0 device
3608 TFTP from server 192.168.1.1; our IP address is 192.168.1.101
3609 Filename 'oftrees/mpc8540ads.dtb'.
3610 Load address: 0x300000
3611 Loading: #
3612 done
3613 Bytes transferred = 4106 (100a hex)
3614 => tftp $loadaddr $bootfile
3615 Speed: 1000, full duplex
3616 Using TSEC0 device
3617 TFTP from server 192.168.1.1; our IP address is 192.168.1.2
3618 Filename 'uImage'.
3619 Load address: 0x200000
3620 Loading:############
3621 done
3622 Bytes transferred = 1029407 (fb51f hex)
3623 => print loadaddr
3624 loadaddr=200000
3625 => print oftaddr
3626 oftaddr=0x300000
3627 => bootm $loadaddr - $oftaddr
3628 ## Booting image at 00200000 ...
3629 Image Name: Linux-2.6.17-dirty
3630 Image Type: PowerPC Linux Kernel Image (gzip compressed)
3631 Data Size: 1029343 Bytes = 1005.2 kB
3632 Load Address: 00000000
3633 Entry Point: 00000000
3634 Verifying Checksum ... OK
3635 Uncompressing Kernel Image ... OK
3636 Booting using flat device tree at 0x300000
3637 Using MPC85xx ADS machine description
3638 Memory CAM mapping: CAM0=256Mb, CAM1=256Mb, CAM2=0Mb residual: 0Mb
3639 [snip]
3640
3641
3642 More About U-Boot Image Types:
3643 ------------------------------
3644
3645 U-Boot supports the following image types:
3646
3647 "Standalone Programs" are directly runnable in the environment
3648 provided by U-Boot; it is expected that (if they behave
3649 well) you can continue to work in U-Boot after return from
3650 the Standalone Program.
3651 "OS Kernel Images" are usually images of some Embedded OS which
3652 will take over control completely. Usually these programs
3653 will install their own set of exception handlers, device
3654 drivers, set up the MMU, etc. - this means, that you cannot
3655 expect to re-enter U-Boot except by resetting the CPU.
3656 "RAMDisk Images" are more or less just data blocks, and their
3657 parameters (address, size) are passed to an OS kernel that is
3658 being started.
3659 "Multi-File Images" contain several images, typically an OS
3660 (Linux) kernel image and one or more data images like
3661 RAMDisks. This construct is useful for instance when you want
3662 to boot over the network using BOOTP etc., where the boot
3663 server provides just a single image file, but you want to get
3664 for instance an OS kernel and a RAMDisk image.
3665
3666 "Multi-File Images" start with a list of image sizes, each
3667 image size (in bytes) specified by an "uint32_t" in network
3668 byte order. This list is terminated by an "(uint32_t)0".
3669 Immediately after the terminating 0 follow the images, one by
3670 one, all aligned on "uint32_t" boundaries (size rounded up to
3671 a multiple of 4 bytes).
3672
3673 "Firmware Images" are binary images containing firmware (like
3674 U-Boot or FPGA images) which usually will be programmed to
3675 flash memory.
3676
3677 "Script files" are command sequences that will be executed by
3678 U-Boot's command interpreter; this feature is especially
3679 useful when you configure U-Boot to use a real shell (hush)
3680 as command interpreter.
3681
3682
3683 Standalone HOWTO:
3684 =================
3685
3686 One of the features of U-Boot is that you can dynamically load and
3687 run "standalone" applications, which can use some resources of
3688 U-Boot like console I/O functions or interrupt services.
3689
3690 Two simple examples are included with the sources:
3691
3692 "Hello World" Demo:
3693 -------------------
3694
3695 'examples/hello_world.c' contains a small "Hello World" Demo
3696 application; it is automatically compiled when you build U-Boot.
3697 It's configured to run at address 0x00040004, so you can play with it
3698 like that:
3699
3700 => loads
3701 ## Ready for S-Record download ...
3702 ~>examples/hello_world.srec
3703 1 2 3 4 5 6 7 8 9 10 11 ...
3704 [file transfer complete]
3705 [connected]
3706 ## Start Addr = 0x00040004
3707
3708 => go 40004 Hello World! This is a test.
3709 ## Starting application at 0x00040004 ...
3710 Hello World
3711 argc = 7
3712 argv[0] = "40004"
3713 argv[1] = "Hello"
3714 argv[2] = "World!"
3715 argv[3] = "This"
3716 argv[4] = "is"
3717 argv[5] = "a"
3718 argv[6] = "test."
3719 argv[7] = "<NULL>"
3720 Hit any key to exit ...
3721
3722 ## Application terminated, rc = 0x0
3723
3724 Another example, which demonstrates how to register a CPM interrupt
3725 handler with the U-Boot code, can be found in 'examples/timer.c'.
3726 Here, a CPM timer is set up to generate an interrupt every second.
3727 The interrupt service routine is trivial, just printing a '.'
3728 character, but this is just a demo program. The application can be
3729 controlled by the following keys:
3730
3731 ? - print current values og the CPM Timer registers
3732 b - enable interrupts and start timer
3733 e - stop timer and disable interrupts
3734 q - quit application
3735
3736 => loads
3737 ## Ready for S-Record download ...
3738 ~>examples/timer.srec
3739 1 2 3 4 5 6 7 8 9 10 11 ...
3740 [file transfer complete]
3741 [connected]
3742 ## Start Addr = 0x00040004
3743
3744 => go 40004
3745 ## Starting application at 0x00040004 ...
3746 TIMERS=0xfff00980
3747 Using timer 1
3748 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
3749
3750 Hit 'b':
3751 [q, b, e, ?] Set interval 1000000 us
3752 Enabling timer
3753 Hit '?':
3754 [q, b, e, ?] ........
3755 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
3756 Hit '?':
3757 [q, b, e, ?] .
3758 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
3759 Hit '?':
3760 [q, b, e, ?] .
3761 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
3762 Hit '?':
3763 [q, b, e, ?] .
3764 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
3765 Hit 'e':
3766 [q, b, e, ?] ...Stopping timer
3767 Hit 'q':
3768 [q, b, e, ?] ## Application terminated, rc = 0x0
3769
3770
3771 Minicom warning:
3772 ================
3773
3774 Over time, many people have reported problems when trying to use the
3775 "minicom" terminal emulation program for serial download. I (wd)
3776 consider minicom to be broken, and recommend not to use it. Under
3777 Unix, I recommend to use C-Kermit for general purpose use (and
3778 especially for kermit binary protocol download ("loadb" command), and
3779 use "cu" for S-Record download ("loads" command).
3780
3781 Nevertheless, if you absolutely want to use it try adding this
3782 configuration to your "File transfer protocols" section:
3783
3784 Name Program Name U/D FullScr IO-Red. Multi
3785 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
3786 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
3787
3788
3789 NetBSD Notes:
3790 =============
3791
3792 Starting at version 0.9.2, U-Boot supports NetBSD both as host
3793 (build U-Boot) and target system (boots NetBSD/mpc8xx).
3794
3795 Building requires a cross environment; it is known to work on
3796 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
3797 need gmake since the Makefiles are not compatible with BSD make).
3798 Note that the cross-powerpc package does not install include files;
3799 attempting to build U-Boot will fail because <machine/ansi.h> is
3800 missing. This file has to be installed and patched manually:
3801
3802 # cd /usr/pkg/cross/powerpc-netbsd/include
3803 # mkdir powerpc
3804 # ln -s powerpc machine
3805 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
3806 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
3807
3808 Native builds *don't* work due to incompatibilities between native
3809 and U-Boot include files.
3810
3811 Booting assumes that (the first part of) the image booted is a
3812 stage-2 loader which in turn loads and then invokes the kernel
3813 proper. Loader sources will eventually appear in the NetBSD source
3814 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
3815 meantime, see ftp://ftp.denx.de/pub/u-boot/ppcboot_stage2.tar.gz
3816
3817
3818 Implementation Internals:
3819 =========================
3820
3821 The following is not intended to be a complete description of every
3822 implementation detail. However, it should help to understand the
3823 inner workings of U-Boot and make it easier to port it to custom
3824 hardware.
3825
3826
3827 Initial Stack, Global Data:
3828 ---------------------------
3829
3830 The implementation of U-Boot is complicated by the fact that U-Boot
3831 starts running out of ROM (flash memory), usually without access to
3832 system RAM (because the memory controller is not initialized yet).
3833 This means that we don't have writable Data or BSS segments, and BSS
3834 is not initialized as zero. To be able to get a C environment working
3835 at all, we have to allocate at least a minimal stack. Implementation
3836 options for this are defined and restricted by the CPU used: Some CPU
3837 models provide on-chip memory (like the IMMR area on MPC8xx and
3838 MPC826x processors), on others (parts of) the data cache can be
3839 locked as (mis-) used as memory, etc.
3840
3841 Chris Hallinan posted a good summary of these issues to the
3842 U-Boot mailing list:
3843
3844 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
3845 From: "Chris Hallinan" <clh@net1plus.com>
3846 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
3847 ...
3848
3849 Correct me if I'm wrong, folks, but the way I understand it
3850 is this: Using DCACHE as initial RAM for Stack, etc, does not
3851 require any physical RAM backing up the cache. The cleverness
3852 is that the cache is being used as a temporary supply of
3853 necessary storage before the SDRAM controller is setup. It's
3854 beyond the scope of this list to explain the details, but you
3855 can see how this works by studying the cache architecture and
3856 operation in the architecture and processor-specific manuals.
3857
3858 OCM is On Chip Memory, which I believe the 405GP has 4K. It
3859 is another option for the system designer to use as an
3860 initial stack/RAM area prior to SDRAM being available. Either
3861 option should work for you. Using CS 4 should be fine if your
3862 board designers haven't used it for something that would
3863 cause you grief during the initial boot! It is frequently not
3864 used.
3865
3866 CONFIG_SYS_INIT_RAM_ADDR should be somewhere that won't interfere
3867 with your processor/board/system design. The default value
3868 you will find in any recent u-boot distribution in
3869 walnut.h should work for you. I'd set it to a value larger
3870 than your SDRAM module. If you have a 64MB SDRAM module, set
3871 it above 400_0000. Just make sure your board has no resources
3872 that are supposed to respond to that address! That code in
3873 start.S has been around a while and should work as is when
3874 you get the config right.
3875
3876 -Chris Hallinan
3877 DS4.COM, Inc.
3878
3879 It is essential to remember this, since it has some impact on the C
3880 code for the initialization procedures:
3881
3882 * Initialized global data (data segment) is read-only. Do not attempt
3883 to write it.
3884
3885 * Do not use any uninitialized global data (or implicitely initialized
3886 as zero data - BSS segment) at all - this is undefined, initiali-
3887 zation is performed later (when relocating to RAM).
3888
3889 * Stack space is very limited. Avoid big data buffers or things like
3890 that.
3891
3892 Having only the stack as writable memory limits means we cannot use
3893 normal global data to share information beween the code. But it
3894 turned out that the implementation of U-Boot can be greatly
3895 simplified by making a global data structure (gd_t) available to all
3896 functions. We could pass a pointer to this data as argument to _all_
3897 functions, but this would bloat the code. Instead we use a feature of
3898 the GCC compiler (Global Register Variables) to share the data: we
3899 place a pointer (gd) to the global data into a register which we
3900 reserve for this purpose.
3901
3902 When choosing a register for such a purpose we are restricted by the
3903 relevant (E)ABI specifications for the current architecture, and by
3904 GCC's implementation.
3905
3906 For PowerPC, the following registers have specific use:
3907 R1: stack pointer
3908 R2: reserved for system use
3909 R3-R4: parameter passing and return values
3910 R5-R10: parameter passing
3911 R13: small data area pointer
3912 R30: GOT pointer
3913 R31: frame pointer
3914
3915 (U-Boot also uses R14 as internal GOT pointer.)
3916
3917 ==> U-Boot will use R2 to hold a pointer to the global data
3918
3919 Note: on PPC, we could use a static initializer (since the
3920 address of the global data structure is known at compile time),
3921 but it turned out that reserving a register results in somewhat
3922 smaller code - although the code savings are not that big (on
3923 average for all boards 752 bytes for the whole U-Boot image,
3924 624 text + 127 data).
3925
3926 On Blackfin, the normal C ABI (except for P3) is followed as documented here:
3927 http://docs.blackfin.uclinux.org/doku.php?id=application_binary_interface
3928
3929 ==> U-Boot will use P3 to hold a pointer to the global data
3930
3931 On ARM, the following registers are used:
3932
3933 R0: function argument word/integer result
3934 R1-R3: function argument word
3935 R9: GOT pointer
3936 R10: stack limit (used only if stack checking if enabled)
3937 R11: argument (frame) pointer
3938 R12: temporary workspace
3939 R13: stack pointer
3940 R14: link register
3941 R15: program counter
3942
3943 ==> U-Boot will use R8 to hold a pointer to the global data
3944
3945 NOTE: DECLARE_GLOBAL_DATA_PTR must be used with file-global scope,
3946 or current versions of GCC may "optimize" the code too much.
3947
3948 Memory Management:
3949 ------------------
3950
3951 U-Boot runs in system state and uses physical addresses, i.e. the
3952 MMU is not used either for address mapping nor for memory protection.
3953
3954 The available memory is mapped to fixed addresses using the memory
3955 controller. In this process, a contiguous block is formed for each
3956 memory type (Flash, SDRAM, SRAM), even when it consists of several
3957 physical memory banks.
3958
3959 U-Boot is installed in the first 128 kB of the first Flash bank (on
3960 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
3961 booting and sizing and initializing DRAM, the code relocates itself
3962 to the upper end of DRAM. Immediately below the U-Boot code some
3963 memory is reserved for use by malloc() [see CONFIG_SYS_MALLOC_LEN
3964 configuration setting]. Below that, a structure with global Board
3965 Info data is placed, followed by the stack (growing downward).
3966
3967 Additionally, some exception handler code is copied to the low 8 kB
3968 of DRAM (0x00000000 ... 0x00001FFF).
3969
3970 So a typical memory configuration with 16 MB of DRAM could look like
3971 this:
3972
3973 0x0000 0000 Exception Vector code
3974 :
3975 0x0000 1FFF
3976 0x0000 2000 Free for Application Use
3977 :
3978 :
3979
3980 :
3981 :
3982 0x00FB FF20 Monitor Stack (Growing downward)
3983 0x00FB FFAC Board Info Data and permanent copy of global data
3984 0x00FC 0000 Malloc Arena
3985 :
3986 0x00FD FFFF
3987 0x00FE 0000 RAM Copy of Monitor Code
3988 ... eventually: LCD or video framebuffer
3989 ... eventually: pRAM (Protected RAM - unchanged by reset)
3990 0x00FF FFFF [End of RAM]
3991
3992
3993 System Initialization:
3994 ----------------------
3995
3996 In the reset configuration, U-Boot starts at the reset entry point
3997 (on most PowerPC systems at address 0x00000100). Because of the reset
3998 configuration for CS0# this is a mirror of the onboard Flash memory.
3999 To be able to re-map memory U-Boot then jumps to its link address.
4000 To be able to implement the initialization code in C, a (small!)
4001 initial stack is set up in the internal Dual Ported RAM (in case CPUs
4002 which provide such a feature like MPC8xx or MPC8260), or in a locked
4003 part of the data cache. After that, U-Boot initializes the CPU core,
4004 the caches and the SIU.
4005
4006 Next, all (potentially) available memory banks are mapped using a
4007 preliminary mapping. For example, we put them on 512 MB boundaries
4008 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
4009 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
4010 programmed for SDRAM access. Using the temporary configuration, a
4011 simple memory test is run that determines the size of the SDRAM
4012 banks.
4013
4014 When there is more than one SDRAM bank, and the banks are of
4015 different size, the largest is mapped first. For equal size, the first
4016 bank (CS2#) is mapped first. The first mapping is always for address
4017 0x00000000, with any additional banks following immediately to create
4018 contiguous memory starting from 0.
4019
4020 Then, the monitor installs itself at the upper end of the SDRAM area
4021 and allocates memory for use by malloc() and for the global Board
4022 Info data; also, the exception vector code is copied to the low RAM
4023 pages, and the final stack is set up.
4024
4025 Only after this relocation will you have a "normal" C environment;
4026 until that you are restricted in several ways, mostly because you are
4027 running from ROM, and because the code will have to be relocated to a
4028 new address in RAM.
4029
4030
4031 U-Boot Porting Guide:
4032 ----------------------
4033
4034 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
4035 list, October 2002]
4036
4037
4038 int main(int argc, char *argv[])
4039 {
4040 sighandler_t no_more_time;
4041
4042 signal(SIGALRM, no_more_time);
4043 alarm(PROJECT_DEADLINE - toSec (3 * WEEK));
4044
4045 if (available_money > available_manpower) {
4046 Pay consultant to port U-Boot;
4047 return 0;
4048 }
4049
4050 Download latest U-Boot source;
4051
4052 Subscribe to u-boot mailing list;
4053
4054 if (clueless)
4055 email("Hi, I am new to U-Boot, how do I get started?");
4056
4057 while (learning) {
4058 Read the README file in the top level directory;
4059 Read http://www.denx.de/twiki/bin/view/DULG/Manual;
4060 Read applicable doc/*.README;
4061 Read the source, Luke;
4062 /* find . -name "*.[chS]" | xargs grep -i <keyword> */
4063 }
4064
4065 if (available_money > toLocalCurrency ($2500))
4066 Buy a BDI3000;
4067 else
4068 Add a lot of aggravation and time;
4069
4070 if (a similar board exists) { /* hopefully... */
4071 cp -a board/<similar> board/<myboard>
4072 cp include/configs/<similar>.h include/configs/<myboard>.h
4073 } else {
4074 Create your own board support subdirectory;
4075 Create your own board include/configs/<myboard>.h file;
4076 }
4077 Edit new board/<myboard> files
4078 Edit new include/configs/<myboard>.h
4079
4080 while (!accepted) {
4081 while (!running) {
4082 do {
4083 Add / modify source code;
4084 } until (compiles);
4085 Debug;
4086 if (clueless)
4087 email("Hi, I am having problems...");
4088 }
4089 Send patch file to the U-Boot email list;
4090 if (reasonable critiques)
4091 Incorporate improvements from email list code review;
4092 else
4093 Defend code as written;
4094 }
4095
4096 return 0;
4097 }
4098
4099 void no_more_time (int sig)
4100 {
4101 hire_a_guru();
4102 }
4103
4104
4105 Coding Standards:
4106 -----------------
4107
4108 All contributions to U-Boot should conform to the Linux kernel
4109 coding style; see the file "Documentation/CodingStyle" and the script
4110 "scripts/Lindent" in your Linux kernel source directory. In sources
4111 originating from U-Boot a style corresponding to "Lindent -pcs" (adding
4112 spaces before parameters to function calls) is actually used.
4113
4114 Source files originating from a different project (for example the
4115 MTD subsystem) are generally exempt from these guidelines and are not
4116 reformated to ease subsequent migration to newer versions of those
4117 sources.
4118
4119 Please note that U-Boot is implemented in C (and to some small parts in
4120 Assembler); no C++ is used, so please do not use C++ style comments (//)
4121 in your code.
4122
4123 Please also stick to the following formatting rules:
4124 - remove any trailing white space
4125 - use TAB characters for indentation, not spaces
4126 - make sure NOT to use DOS '\r\n' line feeds
4127 - do not add more than 2 empty lines to source files
4128 - do not add trailing empty lines to source files
4129
4130 Submissions which do not conform to the standards may be returned
4131 with a request to reformat the changes.
4132
4133
4134 Submitting Patches:
4135 -------------------
4136
4137 Since the number of patches for U-Boot is growing, we need to
4138 establish some rules. Submissions which do not conform to these rules
4139 may be rejected, even when they contain important and valuable stuff.
4140
4141 Please see http://www.denx.de/wiki/U-Boot/Patches for details.
4142
4143 Patches shall be sent to the u-boot mailing list <u-boot@lists.denx.de>;
4144 see http://lists.denx.de/mailman/listinfo/u-boot
4145
4146 When you send a patch, please include the following information with
4147 it:
4148
4149 * For bug fixes: a description of the bug and how your patch fixes
4150 this bug. Please try to include a way of demonstrating that the
4151 patch actually fixes something.
4152
4153 * For new features: a description of the feature and your
4154 implementation.
4155
4156 * A CHANGELOG entry as plaintext (separate from the patch)
4157
4158 * For major contributions, your entry to the CREDITS file
4159
4160 * When you add support for a new board, don't forget to add this
4161 board to the MAKEALL script, too.
4162
4163 * If your patch adds new configuration options, don't forget to
4164 document these in the README file.
4165
4166 * The patch itself. If you are using git (which is *strongly*
4167 recommended) you can easily generate the patch using the
4168 "git-format-patch". If you then use "git-send-email" to send it to
4169 the U-Boot mailing list, you will avoid most of the common problems
4170 with some other mail clients.
4171
4172 If you cannot use git, use "diff -purN OLD NEW". If your version of
4173 diff does not support these options, then get the latest version of
4174 GNU diff.
4175
4176 The current directory when running this command shall be the parent
4177 directory of the U-Boot source tree (i. e. please make sure that
4178 your patch includes sufficient directory information for the
4179 affected files).
4180
4181 We prefer patches as plain text. MIME attachments are discouraged,
4182 and compressed attachments must not be used.
4183
4184 * If one logical set of modifications affects or creates several
4185 files, all these changes shall be submitted in a SINGLE patch file.
4186
4187 * Changesets that contain different, unrelated modifications shall be
4188 submitted as SEPARATE patches, one patch per changeset.
4189
4190
4191 Notes:
4192
4193 * Before sending the patch, run the MAKEALL script on your patched
4194 source tree and make sure that no errors or warnings are reported
4195 for any of the boards.
4196
4197 * Keep your modifications to the necessary minimum: A patch
4198 containing several unrelated changes or arbitrary reformats will be
4199 returned with a request to re-formatting / split it.
4200
4201 * If you modify existing code, make sure that your new code does not
4202 add to the memory footprint of the code ;-) Small is beautiful!
4203 When adding new features, these should compile conditionally only
4204 (using #ifdef), and the resulting code with the new feature
4205 disabled must not need more memory than the old code without your
4206 modification.
4207
4208 * Remember that there is a size limit of 100 kB per message on the
4209 u-boot mailing list. Bigger patches will be moderated. If they are
4210 reasonable and not too big, they will be acknowledged. But patches
4211 bigger than the size limit should be avoided.