]> git.ipfire.org Git - people/ms/u-boot.git/blob - README
* Patch by Steven Scholz, 10 Oct 2003
[people/ms/u-boot.git] / README
1 #
2 # (C) Copyright 2000 - 2002
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 and ARM processors, which can be
29 installed in a boot ROM and used to initialize and test the hardware
30 or to download and run application code.
31
32 The development of U-Boot is closely related to Linux: some parts of
33 the source code originate in the Linux source tree, we have some
34 header files in common, and special provision has been made to
35 support booting of Linux images.
36
37 Some attention has been paid to make this software easily
38 configurable and extendable. For instance, all monitor commands are
39 implemented with the same call interface, so that it's very easy to
40 add new commands. Also, instead of permanently adding rarely used
41 code (for instance hardware test utilities) to the monitor, you can
42 load and run it dynamically.
43
44
45 Status:
46 =======
47
48 In general, all boards for which a configuration option exists in the
49 Makefile have been tested to some extent and can be considered
50 "working". In fact, many of them are used in production systems.
51
52 In case of problems see the CHANGELOG and CREDITS files to find out
53 who contributed the specific port.
54
55
56 Where to get help:
57 ==================
58
59 In case you have questions about, problems with or contributions for
60 U-Boot you should send a message to the U-Boot mailing list at
61 <u-boot-users@lists.sourceforge.net>. There is also an archive of
62 previous traffic on the mailing list - please search the archive
63 before asking FAQ's. Please see
64 http://lists.sourceforge.net/lists/listinfo/u-boot-users/
65
66
67 Where we come from:
68 ===================
69
70 - start from 8xxrom sources
71 - create PPCBoot project (http://sourceforge.net/projects/ppcboot)
72 - clean up code
73 - make it easier to add custom boards
74 - make it possible to add other [PowerPC] CPUs
75 - extend functions, especially:
76 * Provide extended interface to Linux boot loader
77 * S-Record download
78 * network boot
79 * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80 - create ARMBoot project (http://sourceforge.net/projects/armboot)
81 - add other CPU families (starting with ARM)
82 - create U-Boot project (http://sourceforge.net/projects/u-boot)
83
84
85 Names and Spelling:
86 ===================
87
88 The "official" name of this project is "Das U-Boot". The spelling
89 "U-Boot" shall be used in all written text (documentation, comments
90 in source files etc.). Example:
91
92 This is the README file for the U-Boot project.
93
94 File names etc. shall be based on the string "u-boot". Examples:
95
96 include/asm-ppc/u-boot.h
97
98 #include <asm/u-boot.h>
99
100 Variable names, preprocessor constants etc. shall be either based on
101 the string "u_boot" or on "U_BOOT". Example:
102
103 U_BOOT_VERSION u_boot_logo
104 IH_OS_U_BOOT u_boot_hush_start
105
106
107 Versioning:
108 ===========
109
110 U-Boot uses a 3 level version number containing a version, a
111 sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
112 sub-version "34", and patchlevel "4".
113
114 The patchlevel is used to indicate certain stages of development
115 between released versions, i. e. officially released versions of
116 U-Boot will always have a patchlevel of "0".
117
118
119 Directory Hierarchy:
120 ====================
121
122 - board Board dependent files
123 - common Misc architecture independent functions
124 - cpu CPU specific files
125 - disk Code for disk drive partition handling
126 - doc Documentation (don't expect too much)
127 - drivers Commonly used device drivers
128 - dtt Digital Thermometer and Thermostat drivers
129 - examples Example code for standalone applications, etc.
130 - include Header Files
131 - disk Harddisk interface code
132 - net Networking code
133 - ppc Files generic to PowerPC architecture
134 - post Power On Self Test
135 - post/arch Symlink to architecture specific Power On Self Test
136 - post/arch-ppc PowerPC architecture specific Power On Self Test
137 - post/cpu/mpc8260 MPC8260 CPU specific Power On Self Test
138 - post/cpu/mpc8xx MPC8xx CPU specific Power On Self Test
139 - rtc Real Time Clock drivers
140 - tools Tools to build S-Record or U-Boot images, etc.
141
142 - cpu/74xx_7xx Files specific to Motorola MPC74xx and 7xx CPUs
143 - cpu/arm925t Files specific to ARM 925 CPUs
144 - cpu/arm926ejs Files specific to ARM 926 CPUs
145 - cpu/mpc5xx Files specific to Motorola MPC5xx CPUs
146 - cpu/mpc8xx Files specific to Motorola MPC8xx CPUs
147 - cpu/mpc824x Files specific to Motorola MPC824x CPUs
148 - cpu/mpc8260 Files specific to Motorola MPC8260 CPU
149 - cpu/ppc4xx Files specific to IBM 4xx CPUs
150
151
152 - board/LEOX/ Files specific to boards manufactured by The LEOX team
153 - board/LEOX/elpt860 Files specific to ELPT860 boards
154 - board/RPXClassic
155 Files specific to RPXClassic boards
156 - board/RPXlite Files specific to RPXlite boards
157 - board/at91rm9200dk Files specific to AT91RM9200DK boards
158 - board/c2mon Files specific to c2mon boards
159 - board/cmi Files specific to cmi boards
160 - board/cogent Files specific to Cogent boards
161 (need further configuration)
162 Files specific to CPCIISER4 boards
163 - board/cpu86 Files specific to CPU86 boards
164 - board/cray/ Files specific to boards manufactured by Cray
165 - board/cray/L1 Files specific to L1 boards
166 - board/cu824 Files specific to CU824 boards
167 - board/ebony Files specific to IBM Ebony board
168 - board/eric Files specific to ERIC boards
169 - board/esd/ Files specific to boards manufactured by ESD
170 - board/esd/adciop Files specific to ADCIOP boards
171 - board/esd/ar405 Files specific to AR405 boards
172 - board/esd/canbt Files specific to CANBT boards
173 - board/esd/cpci405 Files specific to CPCI405 boards
174 - board/esd/cpciiser4 Files specific to CPCIISER4 boards
175 - board/esd/common Common files for ESD boards
176 - board/esd/dasa_sim Files specific to DASA_SIM boards
177 - board/esd/du405 Files specific to DU405 boards
178 - board/esd/ocrtc Files specific to OCRTC boards
179 - board/esd/pci405 Files specific to PCI405 boards
180 - board/esteem192e
181 Files specific to ESTEEM192E boards
182 - board/etx094 Files specific to ETX_094 boards
183 - board/evb64260
184 Files specific to EVB64260 boards
185 - board/fads Files specific to FADS boards
186 - board/flagadm Files specific to FLAGADM boards
187 - board/gen860t Files specific to GEN860T and GEN860T_SC boards
188 - board/genietv Files specific to GENIETV boards
189 - board/gth Files specific to GTH boards
190 - board/hermes Files specific to HERMES boards
191 - board/hymod Files specific to HYMOD boards
192 - board/icu862 Files specific to ICU862 boards
193 - board/ip860 Files specific to IP860 boards
194 - board/iphase4539
195 Files specific to Interphase4539 boards
196 - board/ivm Files specific to IVMS8/IVML24 boards
197 - board/lantec Files specific to LANTEC boards
198 - board/lwmon Files specific to LWMON boards
199 - board/mbx8xx Files specific to MBX boards
200 - board/mpc8260ads
201 Files specific to MPC8260ADS and PQ2FADS-ZU boards
202 - board/mpl/ Files specific to boards manufactured by MPL
203 - board/mpl/common Common files for MPL boards
204 - board/mpl/pip405 Files specific to PIP405 boards
205 - board/mpl/mip405 Files specific to MIP405 boards
206 - board/mpl/vcma9 Files specific to VCMA9 boards
207 - board/musenki Files specific to MUSEKNI boards
208 - board/mvs1 Files specific to MVS1 boards
209 - board/nx823 Files specific to NX823 boards
210 - board/oxc Files specific to OXC boards
211 - board/omap1510inn
212 Files specific to OMAP 1510 Innovator boards
213 - board/omap1610inn
214 Files specific to OMAP 1610 Innovator boards
215 - board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards
216 - board/pm826 Files specific to PM826 boards
217 - board/ppmc8260
218 Files specific to PPMC8260 boards
219 - board/rpxsuper
220 Files specific to RPXsuper boards
221 - board/rsdproto
222 Files specific to RSDproto boards
223 - board/sandpoint
224 Files specific to Sandpoint boards
225 - board/sbc8260 Files specific to SBC8260 boards
226 - board/sacsng Files specific to SACSng boards
227 - board/siemens Files specific to boards manufactured by Siemens AG
228 - board/siemens/CCM Files specific to CCM boards
229 - board/siemens/IAD210 Files specific to IAD210 boards
230 - board/siemens/SCM Files specific to SCM boards
231 - board/siemens/pcu_e Files specific to PCU_E boards
232 - board/sixnet Files specific to SIXNET boards
233 - board/spd8xx Files specific to SPD8xxTS boards
234 - board/tqm8260 Files specific to TQM8260 boards
235 - board/tqm8xx Files specific to TQM8xxL boards
236 - board/w7o Files specific to W7O boards
237 - board/walnut405
238 Files specific to Walnut405 boards
239 - board/westel/ Files specific to boards manufactured by Westel Wireless
240 - board/westel/amx860 Files specific to AMX860 boards
241 - board/utx8245 Files specific to UTX8245 boards
242 - board/zpc1900 Files specific to Zephyr Engineering ZPC.1900 board
243
244 Software Configuration:
245 =======================
246
247 Configuration is usually done using C preprocessor defines; the
248 rationale behind that is to avoid dead code whenever possible.
249
250 There are two classes of configuration variables:
251
252 * Configuration _OPTIONS_:
253 These are selectable by the user and have names beginning with
254 "CONFIG_".
255
256 * Configuration _SETTINGS_:
257 These depend on the hardware etc. and should not be meddled with if
258 you don't know what you're doing; they have names beginning with
259 "CFG_".
260
261 Later we will add a configuration tool - probably similar to or even
262 identical to what's used for the Linux kernel. Right now, we have to
263 do the configuration by hand, which means creating some symbolic
264 links and editing some configuration files. We use the TQM8xxL boards
265 as an example here.
266
267
268 Selection of Processor Architecture and Board Type:
269 ---------------------------------------------------
270
271 For all supported boards there are ready-to-use default
272 configurations available; just type "make <board_name>_config".
273
274 Example: For a TQM823L module type:
275
276 cd u-boot
277 make TQM823L_config
278
279 For the Cogent platform, you need to specify the cpu type as well;
280 e.g. "make cogent_mpc8xx_config". And also configure the cogent
281 directory according to the instructions in cogent/README.
282
283
284 Configuration Options:
285 ----------------------
286
287 Configuration depends on the combination of board and CPU type; all
288 such information is kept in a configuration file
289 "include/configs/<board_name>.h".
290
291 Example: For a TQM823L module, all configuration settings are in
292 "include/configs/TQM823L.h".
293
294
295 Many of the options are named exactly as the corresponding Linux
296 kernel configuration options. The intention is to make it easier to
297 build a config tool - later.
298
299
300 The following options need to be configured:
301
302 - CPU Type: Define exactly one of
303
304 PowerPC based CPUs:
305 -------------------
306 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
307 or CONFIG_MPC5xx
308 or CONFIG_MPC824X, CONFIG_MPC8260
309 or CONFIG_IOP480
310 or CONFIG_405GP
311 or CONFIG_405EP
312 or CONFIG_440
313 or CONFIG_MPC74xx
314 or CONFIG_750FX
315
316 ARM based CPUs:
317 ---------------
318 CONFIG_SA1110
319 CONFIG_ARM7
320 CONFIG_PXA250
321
322
323 - Board Type: Define exactly one of
324
325 PowerPC based boards:
326 ---------------------
327
328 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
329 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
330 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
331 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
332 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
333 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
334 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
335 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
336 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
337 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
338 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
339 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
340 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
341 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
342 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
343 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
344 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
345 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
346 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
347 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
348 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
349 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
350 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
351 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
352 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
353 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
354 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
355 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
356 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
357 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L,
358 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI,
359 CONFIG_NETVIA, CONFIG_RBC823, CONFIG_ZPC1900
360
361 ARM based boards:
362 -----------------
363
364 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
365 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
366 CONFIG_INNOVATOROMAP1510, CONFIG_INNOVATOROMAP1610
367 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
368 CONFIG_TRAB, CONFIG_VCMA9, CONFIG_AT91RM9200DK
369
370
371 - CPU Module Type: (if CONFIG_COGENT is defined)
372 Define exactly one of
373 CONFIG_CMA286_60_OLD
374 --- FIXME --- not tested yet:
375 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
376 CONFIG_CMA287_23, CONFIG_CMA287_50
377
378 - Motherboard Type: (if CONFIG_COGENT is defined)
379 Define exactly one of
380 CONFIG_CMA101, CONFIG_CMA102
381
382 - Motherboard I/O Modules: (if CONFIG_COGENT is defined)
383 Define one or more of
384 CONFIG_CMA302
385
386 - Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
387 Define one or more of
388 CONFIG_LCD_HEARTBEAT - update a character position on
389 the lcd display every second with
390 a "rotator" |\-/|\-/
391
392 - Board flavour: (if CONFIG_MPC8260ADS is defined)
393 CONFIG_ADSTYPE
394 Possible values are:
395 CFG_8260ADS - original MPC8260ADS
396 CFG_8266ADS - MPC8266ADS (untested)
397 CFG_PQ2FADS - PQ2FADS-ZU or PQ2FADS-VR
398
399
400 - MPC824X Family Member (if CONFIG_MPC824X is defined)
401 Define exactly one of
402 CONFIG_MPC8240, CONFIG_MPC8245
403
404 - 8xx CPU Options: (if using an 8xx cpu)
405 Define one or more of
406 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() cannot work
407 e.g. if there is no 32KHz
408 reference PIT/RTC clock
409
410 - Linux Kernel Interface:
411 CONFIG_CLOCKS_IN_MHZ
412
413 U-Boot stores all clock information in Hz
414 internally. For binary compatibility with older Linux
415 kernels (which expect the clocks passed in the
416 bd_info data to be in MHz) the environment variable
417 "clocks_in_mhz" can be defined so that U-Boot
418 converts clock data to MHZ before passing it to the
419 Linux kernel.
420 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
421 "clocks_in_mhz=1" is automatically included in the
422 default environment.
423
424 CONFIG_MEMSIZE_IN_BYTES [relevant for MIPS only]
425
426 When transfering memsize parameter to linux, some versions
427 expect it to be in bytes, others in MB.
428 Define CONFIG_MEMSIZE_IN_BYTES to make it in bytes.
429
430 - Console Interface:
431 Depending on board, define exactly one serial port
432 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
433 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
434 console by defining CONFIG_8xx_CONS_NONE
435
436 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
437 port routines must be defined elsewhere
438 (i.e. serial_init(), serial_getc(), ...)
439
440 CONFIG_CFB_CONSOLE
441 Enables console device for a color framebuffer. Needs following
442 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
443 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
444 (default big endian)
445 VIDEO_HW_RECTFILL graphic chip supports
446 rectangle fill
447 (cf. smiLynxEM)
448 VIDEO_HW_BITBLT graphic chip supports
449 bit-blit (cf. smiLynxEM)
450 VIDEO_VISIBLE_COLS visible pixel columns
451 (cols=pitch)
452 VIDEO_VISIBLE_ROWS visible pixel rows
453 VIDEO_PIXEL_SIZE bytes per pixel
454 VIDEO_DATA_FORMAT graphic data format
455 (0-5, cf. cfb_console.c)
456 VIDEO_FB_ADRS framebuffer address
457 VIDEO_KBD_INIT_FCT keyboard int fct
458 (i.e. i8042_kbd_init())
459 VIDEO_TSTC_FCT test char fct
460 (i.e. i8042_tstc)
461 VIDEO_GETC_FCT get char fct
462 (i.e. i8042_getc)
463 CONFIG_CONSOLE_CURSOR cursor drawing on/off
464 (requires blink timer
465 cf. i8042.c)
466 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
467 CONFIG_CONSOLE_TIME display time/date info in
468 upper right corner
469 (requires CFG_CMD_DATE)
470 CONFIG_VIDEO_LOGO display Linux logo in
471 upper left corner
472 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
473 linux_logo.h for logo.
474 Requires CONFIG_VIDEO_LOGO
475 CONFIG_CONSOLE_EXTRA_INFO
476 addional board info beside
477 the logo
478
479 When CONFIG_CFB_CONSOLE is defined, video console is
480 default i/o. Serial console can be forced with
481 environment 'console=serial'.
482
483 - Console Baudrate:
484 CONFIG_BAUDRATE - in bps
485 Select one of the baudrates listed in
486 CFG_BAUDRATE_TABLE, see below.
487
488 - Interrupt driven serial port input:
489 CONFIG_SERIAL_SOFTWARE_FIFO
490
491 PPC405GP only.
492 Use an interrupt handler for receiving data on the
493 serial port. It also enables using hardware handshake
494 (RTS/CTS) and UART's built-in FIFO. Set the number of
495 bytes the interrupt driven input buffer should have.
496
497 Set to 0 to disable this feature (this is the default).
498 This will also disable hardware handshake.
499
500 - Console UART Number:
501 CONFIG_UART1_CONSOLE
502
503 IBM PPC4xx only.
504 If defined internal UART1 (and not UART0) is used
505 as default U-Boot console.
506
507 - Boot Delay: CONFIG_BOOTDELAY - in seconds
508 Delay before automatically booting the default image;
509 set to -1 to disable autoboot.
510
511 See doc/README.autoboot for these options that
512 work with CONFIG_BOOTDELAY. None are required.
513 CONFIG_BOOT_RETRY_TIME
514 CONFIG_BOOT_RETRY_MIN
515 CONFIG_AUTOBOOT_KEYED
516 CONFIG_AUTOBOOT_PROMPT
517 CONFIG_AUTOBOOT_DELAY_STR
518 CONFIG_AUTOBOOT_STOP_STR
519 CONFIG_AUTOBOOT_DELAY_STR2
520 CONFIG_AUTOBOOT_STOP_STR2
521 CONFIG_ZERO_BOOTDELAY_CHECK
522 CONFIG_RESET_TO_RETRY
523
524 - Autoboot Command:
525 CONFIG_BOOTCOMMAND
526 Only needed when CONFIG_BOOTDELAY is enabled;
527 define a command string that is automatically executed
528 when no character is read on the console interface
529 within "Boot Delay" after reset.
530
531 CONFIG_BOOTARGS
532 This can be used to pass arguments to the bootm
533 command. The value of CONFIG_BOOTARGS goes into the
534 environment value "bootargs".
535
536 CONFIG_RAMBOOT and CONFIG_NFSBOOT
537 The value of these goes into the environment as
538 "ramboot" and "nfsboot" respectively, and can be used
539 as a convenience, when switching between booting from
540 ram and nfs.
541
542 - Pre-Boot Commands:
543 CONFIG_PREBOOT
544
545 When this option is #defined, the existence of the
546 environment variable "preboot" will be checked
547 immediately before starting the CONFIG_BOOTDELAY
548 countdown and/or running the auto-boot command resp.
549 entering interactive mode.
550
551 This feature is especially useful when "preboot" is
552 automatically generated or modified. For an example
553 see the LWMON board specific code: here "preboot" is
554 modified when the user holds down a certain
555 combination of keys on the (special) keyboard when
556 booting the systems
557
558 - Serial Download Echo Mode:
559 CONFIG_LOADS_ECHO
560 If defined to 1, all characters received during a
561 serial download (using the "loads" command) are
562 echoed back. This might be needed by some terminal
563 emulations (like "cu"), but may as well just take
564 time on others. This setting #define's the initial
565 value of the "loads_echo" environment variable.
566
567 - Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
568 CONFIG_KGDB_BAUDRATE
569 Select one of the baudrates listed in
570 CFG_BAUDRATE_TABLE, see below.
571
572 - Monitor Functions:
573 CONFIG_COMMANDS
574 Most monitor functions can be selected (or
575 de-selected) by adjusting the definition of
576 CONFIG_COMMANDS; to select individual functions,
577 #define CONFIG_COMMANDS by "OR"ing any of the
578 following values:
579
580 #define enables commands:
581 -------------------------
582 CFG_CMD_ASKENV * ask for env variable
583 CFG_CMD_AUTOSCRIPT Autoscript Support
584 CFG_CMD_BDI bdinfo
585 CFG_CMD_BEDBUG Include BedBug Debugger
586 CFG_CMD_BMP * BMP support
587 CFG_CMD_BOOTD bootd
588 CFG_CMD_CACHE icache, dcache
589 CFG_CMD_CONSOLE coninfo
590 CFG_CMD_DATE * support for RTC, date/time...
591 CFG_CMD_DHCP DHCP support
592 CFG_CMD_DIAG * Diagnostics
593 CFG_CMD_DOC * Disk-On-Chip Support
594 CFG_CMD_DTT Digital Therm and Thermostat
595 CFG_CMD_ECHO * echo arguments
596 CFG_CMD_EEPROM * EEPROM read/write support
597 CFG_CMD_ELF bootelf, bootvx
598 CFG_CMD_ENV saveenv
599 CFG_CMD_FDC * Floppy Disk Support
600 CFG_CMD_FAT FAT partition support
601 CFG_CMD_FDOS * Dos diskette Support
602 CFG_CMD_FLASH flinfo, erase, protect
603 CFG_CMD_FPGA FPGA device initialization support
604 CFG_CMD_HWFLOW * RTS/CTS hw flow control
605 CFG_CMD_I2C * I2C serial bus support
606 CFG_CMD_IDE * IDE harddisk support
607 CFG_CMD_IMI iminfo
608 CFG_CMD_IMLS List all found images
609 CFG_CMD_IMMAP * IMMR dump support
610 CFG_CMD_IRQ * irqinfo
611 CFG_CMD_JFFS2 * JFFS2 Support
612 CFG_CMD_KGDB * kgdb
613 CFG_CMD_LOADB loadb
614 CFG_CMD_LOADS loads
615 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
616 loop, mtest
617 CFG_CMD_MISC Misc functions like sleep etc
618 CFG_CMD_MMC MMC memory mapped support
619 CFG_CMD_MII MII utility commands
620 CFG_CMD_NAND * NAND support
621 CFG_CMD_NET bootp, tftpboot, rarpboot
622 CFG_CMD_PCI * pciinfo
623 CFG_CMD_PCMCIA * PCMCIA support
624 CFG_CMD_PING * send ICMP ECHO_REQUEST to network host
625 CFG_CMD_PORTIO Port I/O
626 CFG_CMD_REGINFO * Register dump
627 CFG_CMD_RUN run command in env variable
628 CFG_CMD_SAVES save S record dump
629 CFG_CMD_SCSI * SCSI Support
630 CFG_CMD_SDRAM * print SDRAM configuration information
631 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
632 CFG_CMD_SPI * SPI serial bus support
633 CFG_CMD_USB * USB support
634 CFG_CMD_VFD * VFD support (TRAB)
635 CFG_CMD_BSP * Board SPecific functions
636 -----------------------------------------------
637 CFG_CMD_ALL all
638
639 CFG_CMD_DFL Default configuration; at the moment
640 this is includes all commands, except
641 the ones marked with "*" in the list
642 above.
643
644 If you don't define CONFIG_COMMANDS it defaults to
645 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
646 override the default settings in the respective
647 include file.
648
649 EXAMPLE: If you want all functions except of network
650 support you can write:
651
652 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
653
654
655 Note: Don't enable the "icache" and "dcache" commands
656 (configuration option CFG_CMD_CACHE) unless you know
657 what you (and your U-Boot users) are doing. Data
658 cache cannot be enabled on systems like the 8xx or
659 8260 (where accesses to the IMMR region must be
660 uncached), and it cannot be disabled on all other
661 systems where we (mis-) use the data cache to hold an
662 initial stack and some data.
663
664
665 XXX - this list needs to get updated!
666
667 - Watchdog:
668 CONFIG_WATCHDOG
669 If this variable is defined, it enables watchdog
670 support. There must be support in the platform specific
671 code for a watchdog. For the 8xx and 8260 CPUs, the
672 SIU Watchdog feature is enabled in the SYPCR
673 register.
674
675 - U-Boot Version:
676 CONFIG_VERSION_VARIABLE
677 If this variable is defined, an environment variable
678 named "ver" is created by U-Boot showing the U-Boot
679 version as printed by the "version" command.
680 This variable is readonly.
681
682 - Real-Time Clock:
683
684 When CFG_CMD_DATE is selected, the type of the RTC
685 has to be selected, too. Define exactly one of the
686 following options:
687
688 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
689 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
690 CONFIG_RTC_MC146818 - use MC146818 RTC
691 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
692 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
693 CONFIG_RTC_DS1338 - use Maxim, Inc. DS1338 RTC
694 CONFIG_RTC_DS164x - use Dallas DS164x RTC
695
696 Note that if the RTC uses I2C, then the I2C interface
697 must also be configured. See I2C Support, below.
698
699 - Timestamp Support:
700
701 When CONFIG_TIMESTAMP is selected, the timestamp
702 (date and time) of an image is printed by image
703 commands like bootm or iminfo. This option is
704 automatically enabled when you select CFG_CMD_DATE .
705
706 - Partition Support:
707 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
708 and/or CONFIG_ISO_PARTITION
709
710 If IDE or SCSI support is enabled (CFG_CMD_IDE or
711 CFG_CMD_SCSI) you must configure support for at least
712 one partition type as well.
713
714 - IDE Reset method:
715 CONFIG_IDE_RESET_ROUTINE
716
717 Set this to define that instead of a reset Pin, the
718 routine ide_set_reset(int idereset) will be used.
719
720 - ATAPI Support:
721 CONFIG_ATAPI
722
723 Set this to enable ATAPI support.
724
725 - SCSI Support:
726 At the moment only there is only support for the
727 SYM53C8XX SCSI controller; define
728 CONFIG_SCSI_SYM53C8XX to enable it.
729
730 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
731 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
732 CFG_SCSI_MAX_LUN] can be adjusted to define the
733 maximum numbers of LUNs, SCSI ID's and target
734 devices.
735 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
736
737 - NETWORK Support (PCI):
738 CONFIG_E1000
739 Support for Intel 8254x gigabit chips.
740
741 CONFIG_EEPRO100
742 Support for Intel 82557/82559/82559ER chips.
743 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
744 write routine for first time initialisation.
745
746 CONFIG_TULIP
747 Support for Digital 2114x chips.
748 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
749 modem chip initialisation (KS8761/QS6611).
750
751 CONFIG_NATSEMI
752 Support for National dp83815 chips.
753
754 CONFIG_NS8382X
755 Support for National dp8382[01] gigabit chips.
756
757 - NETWORK Support (other):
758
759 CONFIG_DRIVER_LAN91C96
760 Support for SMSC's LAN91C96 chips.
761
762 CONFIG_LAN91C96_BASE
763 Define this to hold the physical address
764 of the LAN91C96's I/O space
765
766 CONFIG_LAN91C96_USE_32_BIT
767 Define this to enable 32 bit addressing
768
769 - USB Support:
770 At the moment only the UHCI host controller is
771 supported (PIP405, MIP405); define
772 CONFIG_USB_UHCI to enable it.
773 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
774 end define CONFIG_USB_STORAGE to enable the USB
775 storage devices.
776 Note:
777 Supported are USB Keyboards and USB Floppy drives
778 (TEAC FD-05PUB).
779
780 - MMC Support:
781 The MMC controller on the Intel PXA is supported. To
782 enable this define CONFIG_MMC. The MMC can be
783 accessed from the boot prompt by mapping the device
784 to physical memory similar to flash. Command line is
785 enabled with CFG_CMD_MMC. The MMC driver also works with
786 the FAT fs. This is enabled with CFG_CMD_FAT.
787
788 - Keyboard Support:
789 CONFIG_ISA_KEYBOARD
790
791 Define this to enable standard (PC-Style) keyboard
792 support
793
794 CONFIG_I8042_KBD
795 Standard PC keyboard driver with US (is default) and
796 GERMAN key layout (switch via environment 'keymap=de') support.
797 Export function i8042_kbd_init, i8042_tstc and i8042_getc
798 for cfb_console. Supports cursor blinking.
799
800 - Video support:
801 CONFIG_VIDEO
802
803 Define this to enable video support (for output to
804 video).
805
806 CONFIG_VIDEO_CT69000
807
808 Enable Chips & Technologies 69000 Video chip
809
810 CONFIG_VIDEO_SMI_LYNXEM
811 Enable Silicon Motion SMI 712/710/810 Video chip
812 Videomode are selected via environment 'videomode' with
813 standard LiLo mode numbers.
814 Following modes are supported (* is default):
815
816 800x600 1024x768 1280x1024
817 256 (8bit) 303* 305 307
818 65536 (16bit) 314 317 31a
819 16,7 Mill (24bit) 315 318 31b
820 (i.e. setenv videomode 317; saveenv; reset;)
821
822 CONFIG_VIDEO_SED13806
823 Enable Epson SED13806 driver. This driver supports 8bpp
824 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
825 or CONFIG_VIDEO_SED13806_16BPP
826
827 - Keyboard Support:
828 CONFIG_KEYBOARD
829
830 Define this to enable a custom keyboard support.
831 This simply calls drv_keyboard_init() which must be
832 defined in your board-specific files.
833 The only board using this so far is RBC823.
834
835 - LCD Support: CONFIG_LCD
836
837 Define this to enable LCD support (for output to LCD
838 display); also select one of the supported displays
839 by defining one of these:
840
841 CONFIG_NEC_NL6648AC33:
842
843 NEC NL6648AC33-18. Active, color, single scan.
844
845 CONFIG_NEC_NL6648BC20
846
847 NEC NL6648BC20-08. 6.5", 640x480.
848 Active, color, single scan.
849
850 CONFIG_SHARP_16x9
851
852 Sharp 320x240. Active, color, single scan.
853 It isn't 16x9, and I am not sure what it is.
854
855 CONFIG_SHARP_LQ64D341
856
857 Sharp LQ64D341 display, 640x480.
858 Active, color, single scan.
859
860 CONFIG_HLD1045
861
862 HLD1045 display, 640x480.
863 Active, color, single scan.
864
865 CONFIG_OPTREX_BW
866
867 Optrex CBL50840-2 NF-FW 99 22 M5
868 or
869 Hitachi LMG6912RPFC-00T
870 or
871 Hitachi SP14Q002
872
873 320x240. Black & white.
874
875 Normally display is black on white background; define
876 CFG_WHITE_ON_BLACK to get it inverted.
877
878 - Splash Screen Support: CONFIG_SPLASH_SCREEN
879
880 If this option is set, the environment is checked for
881 a variable "splashimage". If found, the usual display
882 of logo, copyright and system information on the LCD
883 is supressed and the BMP image at the address
884 specified in "splashimage" is loaded instead. The
885 console is redirected to the "nulldev", too. This
886 allows for a "silent" boot where a splash screen is
887 loaded very quickly after power-on.
888
889 - Compression support:
890 CONFIG_BZIP2
891
892 If this option is set, support for bzip2 compressed
893 images is included. If not, only uncompressed and gzip
894 compressed images are supported.
895
896 NOTE: the bzip2 algorithm requires a lot of RAM, so
897 the malloc area (as defined by CFG_MALLOC_LEN) should
898 be at least 4MB.
899
900 - Ethernet address:
901 CONFIG_ETHADDR
902 CONFIG_ETH2ADDR
903 CONFIG_ETH3ADDR
904
905 Define a default value for ethernet address to use
906 for the respective ethernet interface, in case this
907 is not determined automatically.
908
909 - IP address:
910 CONFIG_IPADDR
911
912 Define a default value for the IP address to use for
913 the default ethernet interface, in case this is not
914 determined through e.g. bootp.
915
916 - Server IP address:
917 CONFIG_SERVERIP
918
919 Defines a default value for theIP address of a TFTP
920 server to contact when using the "tftboot" command.
921
922 - BOOTP Recovery Mode:
923 CONFIG_BOOTP_RANDOM_DELAY
924
925 If you have many targets in a network that try to
926 boot using BOOTP, you may want to avoid that all
927 systems send out BOOTP requests at precisely the same
928 moment (which would happen for instance at recovery
929 from a power failure, when all systems will try to
930 boot, thus flooding the BOOTP server. Defining
931 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
932 inserted before sending out BOOTP requests. The
933 following delays are insterted then:
934
935 1st BOOTP request: delay 0 ... 1 sec
936 2nd BOOTP request: delay 0 ... 2 sec
937 3rd BOOTP request: delay 0 ... 4 sec
938 4th and following
939 BOOTP requests: delay 0 ... 8 sec
940
941 - DHCP Advanced Options:
942 CONFIG_BOOTP_MASK
943
944 You can fine tune the DHCP functionality by adding
945 these flags to the CONFIG_BOOTP_MASK define:
946
947 CONFIG_BOOTP_DNS2 - If a DHCP client requests the DNS
948 serverip from a DHCP server, it is possible that more
949 than one DNS serverip is offered to the client.
950 If CONFIG_BOOTP_DNS2 is enabled, the secondary DNS
951 serverip will be stored in the additional environment
952 variable "dnsip2". The first DNS serverip is always
953 stored in the variable "dnsip", when CONFIG_BOOTP_DNS
954 is added to the CONFIG_BOOTP_MASK.
955
956 CONFIG_BOOTP_SEND_HOSTNAME - Some DHCP servers are capable
957 to do a dynamic update of a DNS server. To do this, they
958 need the hostname of the DHCP requester.
959 If CONFIG_BOOP_SEND_HOSTNAME is added to the
960 CONFIG_BOOTP_MASK, the content of the "hostname"
961 environment variable is passed as option 12 to
962 the DHCP server.
963
964 - Status LED: CONFIG_STATUS_LED
965
966 Several configurations allow to display the current
967 status using a LED. For instance, the LED will blink
968 fast while running U-Boot code, stop blinking as
969 soon as a reply to a BOOTP request was received, and
970 start blinking slow once the Linux kernel is running
971 (supported by a status LED driver in the Linux
972 kernel). Defining CONFIG_STATUS_LED enables this
973 feature in U-Boot.
974
975 - CAN Support: CONFIG_CAN_DRIVER
976
977 Defining CONFIG_CAN_DRIVER enables CAN driver support
978 on those systems that support this (optional)
979 feature, like the TQM8xxL modules.
980
981 - I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
982
983 These enable I2C serial bus commands. Defining either of
984 (but not both of) CONFIG_HARD_I2C or CONFIG_SOFT_I2C will
985 include the appropriate I2C driver for the selected cpu.
986
987 This will allow you to use i2c commands at the u-boot
988 command line (as long as you set CFG_CMD_I2C in
989 CONFIG_COMMANDS) and communicate with i2c based realtime
990 clock chips. See common/cmd_i2c.c for a description of the
991 command line interface.
992
993 CONFIG_HARD_I2C selects the CPM hardware driver for I2C.
994
995 CONFIG_SOFT_I2C configures u-boot to use a software (aka
996 bit-banging) driver instead of CPM or similar hardware
997 support for I2C.
998
999 There are several other quantities that must also be
1000 defined when you define CONFIG_HARD_I2C or CONFIG_SOFT_I2C.
1001
1002 In both cases you will need to define CFG_I2C_SPEED
1003 to be the frequency (in Hz) at which you wish your i2c bus
1004 to run and CFG_I2C_SLAVE to be the address of this node (ie
1005 the cpu's i2c node address).
1006
1007 Now, the u-boot i2c code for the mpc8xx (cpu/mpc8xx/i2c.c)
1008 sets the cpu up as a master node and so its address should
1009 therefore be cleared to 0 (See, eg, MPC823e User's Manual
1010 p.16-473). So, set CFG_I2C_SLAVE to 0.
1011
1012 That's all that's required for CONFIG_HARD_I2C.
1013
1014 If you use the software i2c interface (CONFIG_SOFT_I2C)
1015 then the following macros need to be defined (examples are
1016 from include/configs/lwmon.h):
1017
1018 I2C_INIT
1019
1020 (Optional). Any commands necessary to enable the I2C
1021 controller or configure ports.
1022
1023 eg: #define I2C_INIT (immr->im_cpm.cp_pbdir |= PB_SCL)
1024
1025 I2C_PORT
1026
1027 (Only for MPC8260 CPU). The I/O port to use (the code
1028 assumes both bits are on the same port). Valid values
1029 are 0..3 for ports A..D.
1030
1031 I2C_ACTIVE
1032
1033 The code necessary to make the I2C data line active
1034 (driven). If the data line is open collector, this
1035 define can be null.
1036
1037 eg: #define I2C_ACTIVE (immr->im_cpm.cp_pbdir |= PB_SDA)
1038
1039 I2C_TRISTATE
1040
1041 The code necessary to make the I2C data line tri-stated
1042 (inactive). If the data line is open collector, this
1043 define can be null.
1044
1045 eg: #define I2C_TRISTATE (immr->im_cpm.cp_pbdir &= ~PB_SDA)
1046
1047 I2C_READ
1048
1049 Code that returns TRUE if the I2C data line is high,
1050 FALSE if it is low.
1051
1052 eg: #define I2C_READ ((immr->im_cpm.cp_pbdat & PB_SDA) != 0)
1053
1054 I2C_SDA(bit)
1055
1056 If <bit> is TRUE, sets the I2C data line high. If it
1057 is FALSE, it clears it (low).
1058
1059 eg: #define I2C_SDA(bit) \
1060 if(bit) immr->im_cpm.cp_pbdat |= PB_SDA; \
1061 else immr->im_cpm.cp_pbdat &= ~PB_SDA
1062
1063 I2C_SCL(bit)
1064
1065 If <bit> is TRUE, sets the I2C clock line high. If it
1066 is FALSE, it clears it (low).
1067
1068 eg: #define I2C_SCL(bit) \
1069 if(bit) immr->im_cpm.cp_pbdat |= PB_SCL; \
1070 else immr->im_cpm.cp_pbdat &= ~PB_SCL
1071
1072 I2C_DELAY
1073
1074 This delay is invoked four times per clock cycle so this
1075 controls the rate of data transfer. The data rate thus
1076 is 1 / (I2C_DELAY * 4). Often defined to be something
1077 like:
1078
1079 #define I2C_DELAY udelay(2)
1080
1081 CFG_I2C_INIT_BOARD
1082
1083 When a board is reset during an i2c bus transfer
1084 chips might think that the current transfer is still
1085 in progress. On some boards it is possible to access
1086 the i2c SCLK line directly, either by using the
1087 processor pin as a GPIO or by having a second pin
1088 connected to the bus. If this option is defined a
1089 custom i2c_init_board() routine in boards/xxx/board.c
1090 is run early in the boot sequence.
1091
1092 - SPI Support: CONFIG_SPI
1093
1094 Enables SPI driver (so far only tested with
1095 SPI EEPROM, also an instance works with Crystal A/D and
1096 D/As on the SACSng board)
1097
1098 CONFIG_SPI_X
1099
1100 Enables extended (16-bit) SPI EEPROM addressing.
1101 (symmetrical to CONFIG_I2C_X)
1102
1103 CONFIG_SOFT_SPI
1104
1105 Enables a software (bit-bang) SPI driver rather than
1106 using hardware support. This is a general purpose
1107 driver that only requires three general I/O port pins
1108 (two outputs, one input) to function. If this is
1109 defined, the board configuration must define several
1110 SPI configuration items (port pins to use, etc). For
1111 an example, see include/configs/sacsng.h.
1112
1113 - FPGA Support: CONFIG_FPGA_COUNT
1114
1115 Specify the number of FPGA devices to support.
1116
1117 CONFIG_FPGA
1118
1119 Used to specify the types of FPGA devices. For
1120 example,
1121 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1122
1123 CFG_FPGA_PROG_FEEDBACK
1124
1125 Enable printing of hash marks during FPGA
1126 configuration.
1127
1128 CFG_FPGA_CHECK_BUSY
1129
1130 Enable checks on FPGA configuration interface busy
1131 status by the configuration function. This option
1132 will require a board or device specific function to
1133 be written.
1134
1135 CONFIG_FPGA_DELAY
1136
1137 If defined, a function that provides delays in the
1138 FPGA configuration driver.
1139
1140 CFG_FPGA_CHECK_CTRLC
1141
1142 Allow Control-C to interrupt FPGA configuration
1143
1144 CFG_FPGA_CHECK_ERROR
1145
1146 Check for configuration errors during FPGA bitfile
1147 loading. For example, abort during Virtex II
1148 configuration if the INIT_B line goes low (which
1149 indicated a CRC error).
1150
1151 CFG_FPGA_WAIT_INIT
1152
1153 Maximum time to wait for the INIT_B line to deassert
1154 after PROB_B has been deasserted during a Virtex II
1155 FPGA configuration sequence. The default time is 500 mS.
1156
1157 CFG_FPGA_WAIT_BUSY
1158
1159 Maximum time to wait for BUSY to deassert during
1160 Virtex II FPGA configuration. The default is 5 mS.
1161
1162 CFG_FPGA_WAIT_CONFIG
1163
1164 Time to wait after FPGA configuration. The default is
1165 200 mS.
1166
1167 - FPGA Support: CONFIG_FPGA_COUNT
1168
1169 Specify the number of FPGA devices to support.
1170
1171 CONFIG_FPGA
1172
1173 Used to specify the types of FPGA devices. For example,
1174 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1175
1176 CFG_FPGA_PROG_FEEDBACK
1177
1178 Enable printing of hash marks during FPGA configuration.
1179
1180 CFG_FPGA_CHECK_BUSY
1181
1182 Enable checks on FPGA configuration interface busy
1183 status by the configuration function. This option
1184 will require a board or device specific function to
1185 be written.
1186
1187 CONFIG_FPGA_DELAY
1188
1189 If defined, a function that provides delays in the FPGA
1190 configuration driver.
1191
1192 CFG_FPGA_CHECK_CTRLC
1193 Allow Control-C to interrupt FPGA configuration
1194
1195 CFG_FPGA_CHECK_ERROR
1196
1197 Check for configuration errors during FPGA bitfile
1198 loading. For example, abort during Virtex II
1199 configuration if the INIT_B line goes low (which
1200 indicated a CRC error).
1201
1202 CFG_FPGA_WAIT_INIT
1203
1204 Maximum time to wait for the INIT_B line to deassert
1205 after PROB_B has been deasserted during a Virtex II
1206 FPGA configuration sequence. The default time is 500
1207 mS.
1208
1209 CFG_FPGA_WAIT_BUSY
1210
1211 Maximum time to wait for BUSY to deassert during
1212 Virtex II FPGA configuration. The default is 5 mS.
1213
1214 CFG_FPGA_WAIT_CONFIG
1215
1216 Time to wait after FPGA configuration. The default is
1217 200 mS.
1218
1219 - Configuration Management:
1220 CONFIG_IDENT_STRING
1221
1222 If defined, this string will be added to the U-Boot
1223 version information (U_BOOT_VERSION)
1224
1225 - Vendor Parameter Protection:
1226
1227 U-Boot considers the values of the environment
1228 variables "serial#" (Board Serial Number) and
1229 "ethaddr" (Ethernet Address) to be parameters that
1230 are set once by the board vendor / manufacturer, and
1231 protects these variables from casual modification by
1232 the user. Once set, these variables are read-only,
1233 and write or delete attempts are rejected. You can
1234 change this behviour:
1235
1236 If CONFIG_ENV_OVERWRITE is #defined in your config
1237 file, the write protection for vendor parameters is
1238 completely disabled. Anybody can change or delete
1239 these parameters.
1240
1241 Alternatively, if you #define _both_ CONFIG_ETHADDR
1242 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1243 ethernet address is installed in the environment,
1244 which can be changed exactly ONCE by the user. [The
1245 serial# is unaffected by this, i. e. it remains
1246 read-only.]
1247
1248 - Protected RAM:
1249 CONFIG_PRAM
1250
1251 Define this variable to enable the reservation of
1252 "protected RAM", i. e. RAM which is not overwritten
1253 by U-Boot. Define CONFIG_PRAM to hold the number of
1254 kB you want to reserve for pRAM. You can overwrite
1255 this default value by defining an environment
1256 variable "pram" to the number of kB you want to
1257 reserve. Note that the board info structure will
1258 still show the full amount of RAM. If pRAM is
1259 reserved, a new environment variable "mem" will
1260 automatically be defined to hold the amount of
1261 remaining RAM in a form that can be passed as boot
1262 argument to Linux, for instance like that:
1263
1264 setenv bootargs ... mem=\$(mem)
1265 saveenv
1266
1267 This way you can tell Linux not to use this memory,
1268 either, which results in a memory region that will
1269 not be affected by reboots.
1270
1271 *WARNING* If your board configuration uses automatic
1272 detection of the RAM size, you must make sure that
1273 this memory test is non-destructive. So far, the
1274 following board configurations are known to be
1275 "pRAM-clean":
1276
1277 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1278 HERMES, IP860, RPXlite, LWMON, LANTEC,
1279 PCU_E, FLAGADM, TQM8260
1280
1281 - Error Recovery:
1282 CONFIG_PANIC_HANG
1283
1284 Define this variable to stop the system in case of a
1285 fatal error, so that you have to reset it manually.
1286 This is probably NOT a good idea for an embedded
1287 system where you want to system to reboot
1288 automatically as fast as possible, but it may be
1289 useful during development since you can try to debug
1290 the conditions that lead to the situation.
1291
1292 CONFIG_NET_RETRY_COUNT
1293
1294 This variable defines the number of retries for
1295 network operations like ARP, RARP, TFTP, or BOOTP
1296 before giving up the operation. If not defined, a
1297 default value of 5 is used.
1298
1299 - Command Interpreter:
1300 CFG_HUSH_PARSER
1301
1302 Define this variable to enable the "hush" shell (from
1303 Busybox) as command line interpreter, thus enabling
1304 powerful command line syntax like
1305 if...then...else...fi conditionals or `&&' and '||'
1306 constructs ("shell scripts").
1307
1308 If undefined, you get the old, much simpler behaviour
1309 with a somewhat smaller memory footprint.
1310
1311
1312 CFG_PROMPT_HUSH_PS2
1313
1314 This defines the secondary prompt string, which is
1315 printed when the command interpreter needs more input
1316 to complete a command. Usually "> ".
1317
1318 Note:
1319
1320 In the current implementation, the local variables
1321 space and global environment variables space are
1322 separated. Local variables are those you define by
1323 simply typing `name=value'. To access a local
1324 variable later on, you have write `$name' or
1325 `${name}'; to execute the contents of a variable
1326 directly type `$name' at the command prompt.
1327
1328 Global environment variables are those you use
1329 setenv/printenv to work with. To run a command stored
1330 in such a variable, you need to use the run command,
1331 and you must not use the '$' sign to access them.
1332
1333 To store commands and special characters in a
1334 variable, please use double quotation marks
1335 surrounding the whole text of the variable, instead
1336 of the backslashes before semicolons and special
1337 symbols.
1338
1339 - Default Environment
1340 CONFIG_EXTRA_ENV_SETTINGS
1341
1342 Define this to contain any number of null terminated
1343 strings (variable = value pairs) that will be part of
1344 the default environment compiled into the boot image.
1345
1346 For example, place something like this in your
1347 board's config file:
1348
1349 #define CONFIG_EXTRA_ENV_SETTINGS \
1350 "myvar1=value1\0" \
1351 "myvar2=value2\0"
1352
1353 Warning: This method is based on knowledge about the
1354 internal format how the environment is stored by the
1355 U-Boot code. This is NOT an official, exported
1356 interface! Although it is unlikely that this format
1357 will change soon, there is no guarantee either.
1358 You better know what you are doing here.
1359
1360 Note: overly (ab)use of the default environment is
1361 discouraged. Make sure to check other ways to preset
1362 the environment like the autoscript function or the
1363 boot command first.
1364
1365 - DataFlash Support
1366 CONFIG_HAS_DATAFLASH
1367
1368 Defining this option enables DataFlash features and
1369 allows to read/write in Dataflash via the standard
1370 commands cp, md...
1371
1372 - Show boot progress
1373 CONFIG_SHOW_BOOT_PROGRESS
1374
1375 Defining this option allows to add some board-
1376 specific code (calling a user-provided function
1377 "show_boot_progress(int)") that enables you to show
1378 the system's boot progress on some display (for
1379 example, some LED's) on your board. At the moment,
1380 the following checkpoints are implemented:
1381
1382 Arg Where When
1383 1 common/cmd_bootm.c before attempting to boot an image
1384 -1 common/cmd_bootm.c Image header has bad magic number
1385 2 common/cmd_bootm.c Image header has correct magic number
1386 -2 common/cmd_bootm.c Image header has bad checksum
1387 3 common/cmd_bootm.c Image header has correct checksum
1388 -3 common/cmd_bootm.c Image data has bad checksum
1389 4 common/cmd_bootm.c Image data has correct checksum
1390 -4 common/cmd_bootm.c Image is for unsupported architecture
1391 5 common/cmd_bootm.c Architecture check OK
1392 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1393 6 common/cmd_bootm.c Image Type check OK
1394 -6 common/cmd_bootm.c gunzip uncompression error
1395 -7 common/cmd_bootm.c Unimplemented compression type
1396 7 common/cmd_bootm.c Uncompression OK
1397 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1398 8 common/cmd_bootm.c Image Type check OK
1399 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1400 9 common/cmd_bootm.c Start initial ramdisk verification
1401 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1402 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1403 10 common/cmd_bootm.c Ramdisk header is OK
1404 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1405 11 common/cmd_bootm.c Ramdisk data has correct checksum
1406 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1407 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1408 13 common/cmd_bootm.c Start multifile image verification
1409 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1410 15 common/cmd_bootm.c All preparation done, transferring control to OS
1411
1412 -1 common/cmd_doc.c Bad usage of "doc" command
1413 -1 common/cmd_doc.c No boot device
1414 -1 common/cmd_doc.c Unknown Chip ID on boot device
1415 -1 common/cmd_doc.c Read Error on boot device
1416 -1 common/cmd_doc.c Image header has bad magic number
1417
1418 -1 common/cmd_ide.c Bad usage of "ide" command
1419 -1 common/cmd_ide.c No boot device
1420 -1 common/cmd_ide.c Unknown boot device
1421 -1 common/cmd_ide.c Unknown partition table
1422 -1 common/cmd_ide.c Invalid partition type
1423 -1 common/cmd_ide.c Read Error on boot device
1424 -1 common/cmd_ide.c Image header has bad magic number
1425
1426 -1 common/cmd_nand.c Bad usage of "nand" command
1427 -1 common/cmd_nand.c No boot device
1428 -1 common/cmd_nand.c Unknown Chip ID on boot device
1429 -1 common/cmd_nand.c Read Error on boot device
1430 -1 common/cmd_nand.c Image header has bad magic number
1431
1432 -1 common/env_common.c Environment has a bad CRC, using default
1433
1434
1435 Modem Support:
1436 --------------
1437
1438 [so far only for SMDK2400 and TRAB boards]
1439
1440 - Modem support endable:
1441 CONFIG_MODEM_SUPPORT
1442
1443 - RTS/CTS Flow control enable:
1444 CONFIG_HWFLOW
1445
1446 - Modem debug support:
1447 CONFIG_MODEM_SUPPORT_DEBUG
1448
1449 Enables debugging stuff (char screen[1024], dbg())
1450 for modem support. Useful only with BDI2000.
1451
1452 - General:
1453
1454 In the target system modem support is enabled when a
1455 specific key (key combination) is pressed during
1456 power-on. Otherwise U-Boot will boot normally
1457 (autoboot). The key_pressed() fuction is called from
1458 board_init(). Currently key_pressed() is a dummy
1459 function, returning 1 and thus enabling modem
1460 initialization.
1461
1462 If there are no modem init strings in the
1463 environment, U-Boot proceed to autoboot; the
1464 previous output (banner, info printfs) will be
1465 supressed, though.
1466
1467 See also: doc/README.Modem
1468
1469
1470 Configuration Settings:
1471 -----------------------
1472
1473 - CFG_LONGHELP: Defined when you want long help messages included;
1474 undefine this when you're short of memory.
1475
1476 - CFG_PROMPT: This is what U-Boot prints on the console to
1477 prompt for user input.
1478
1479 - CFG_CBSIZE: Buffer size for input from the Console
1480
1481 - CFG_PBSIZE: Buffer size for Console output
1482
1483 - CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1484
1485 - CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1486 the application (usually a Linux kernel) when it is
1487 booted
1488
1489 - CFG_BAUDRATE_TABLE:
1490 List of legal baudrate settings for this board.
1491
1492 - CFG_CONSOLE_INFO_QUIET
1493 Suppress display of console information at boot.
1494
1495 - CFG_CONSOLE_IS_IN_ENV
1496 If the board specific function
1497 extern int overwrite_console (void);
1498 returns 1, the stdin, stderr and stdout are switched to the
1499 serial port, else the settings in the environment are used.
1500
1501 - CFG_CONSOLE_OVERWRITE_ROUTINE
1502 Enable the call to overwrite_console().
1503
1504 - CFG_CONSOLE_ENV_OVERWRITE
1505 Enable overwrite of previous console environment settings.
1506
1507 - CFG_MEMTEST_START, CFG_MEMTEST_END:
1508 Begin and End addresses of the area used by the
1509 simple memory test.
1510
1511 - CFG_ALT_MEMTEST:
1512 Enable an alternate, more extensive memory test.
1513
1514 - CFG_MEMTEST_SCRATCH:
1515 Scratch address used by the alternate memory test
1516 You only need to set this if address zero isn't writeable
1517
1518 - CFG_TFTP_LOADADDR:
1519 Default load address for network file downloads
1520
1521 - CFG_LOADS_BAUD_CHANGE:
1522 Enable temporary baudrate change while serial download
1523
1524 - CFG_SDRAM_BASE:
1525 Physical start address of SDRAM. _Must_ be 0 here.
1526
1527 - CFG_MBIO_BASE:
1528 Physical start address of Motherboard I/O (if using a
1529 Cogent motherboard)
1530
1531 - CFG_FLASH_BASE:
1532 Physical start address of Flash memory.
1533
1534 - CFG_MONITOR_BASE:
1535 Physical start address of boot monitor code (set by
1536 make config files to be same as the text base address
1537 (TEXT_BASE) used when linking) - same as
1538 CFG_FLASH_BASE when booting from flash.
1539
1540 - CFG_MONITOR_LEN:
1541 Size of memory reserved for monitor code, used to
1542 determine _at_compile_time_ (!) if the environment is
1543 embedded within the U-Boot image, or in a separate
1544 flash sector.
1545
1546 - CFG_MALLOC_LEN:
1547 Size of DRAM reserved for malloc() use.
1548
1549 - CFG_BOOTMAPSZ:
1550 Maximum size of memory mapped by the startup code of
1551 the Linux kernel; all data that must be processed by
1552 the Linux kernel (bd_info, boot arguments, eventually
1553 initrd image) must be put below this limit.
1554
1555 - CFG_MAX_FLASH_BANKS:
1556 Max number of Flash memory banks
1557
1558 - CFG_MAX_FLASH_SECT:
1559 Max number of sectors on a Flash chip
1560
1561 - CFG_FLASH_ERASE_TOUT:
1562 Timeout for Flash erase operations (in ms)
1563
1564 - CFG_FLASH_WRITE_TOUT:
1565 Timeout for Flash write operations (in ms)
1566
1567 - CFG_FLASH_LOCK_TOUT
1568 Timeout for Flash set sector lock bit operation (in ms)
1569
1570 - CFG_FLASH_UNLOCK_TOUT
1571 Timeout for Flash clear lock bits operation (in ms)
1572
1573 - CFG_FLASH_PROTECTION
1574 If defined, hardware flash sectors protection is used
1575 instead of U-Boot software protection.
1576
1577 - CFG_DIRECT_FLASH_TFTP:
1578
1579 Enable TFTP transfers directly to flash memory;
1580 without this option such a download has to be
1581 performed in two steps: (1) download to RAM, and (2)
1582 copy from RAM to flash.
1583
1584 The two-step approach is usually more reliable, since
1585 you can check if the download worked before you erase
1586 the flash, but in some situations (when sytem RAM is
1587 too limited to allow for a tempory copy of the
1588 downloaded image) this option may be very useful.
1589
1590 - CFG_FLASH_CFI:
1591 Define if the flash driver uses extra elements in the
1592 common flash structure for storing flash geometry
1593
1594 - CFG_RX_ETH_BUFFER:
1595 Defines the number of ethernet receive buffers. On some
1596 ethernet controllers it is recommended to set this value
1597 to 8 or even higher (EEPRO100 or 405 EMAC), since all
1598 buffers can be full shortly after enabling the interface
1599 on high ethernet traffic.
1600 Defaults to 4 if not defined.
1601
1602 The following definitions that deal with the placement and management
1603 of environment data (variable area); in general, we support the
1604 following configurations:
1605
1606 - CFG_ENV_IS_IN_FLASH:
1607
1608 Define this if the environment is in flash memory.
1609
1610 a) The environment occupies one whole flash sector, which is
1611 "embedded" in the text segment with the U-Boot code. This
1612 happens usually with "bottom boot sector" or "top boot
1613 sector" type flash chips, which have several smaller
1614 sectors at the start or the end. For instance, such a
1615 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1616 such a case you would place the environment in one of the
1617 4 kB sectors - with U-Boot code before and after it. With
1618 "top boot sector" type flash chips, you would put the
1619 environment in one of the last sectors, leaving a gap
1620 between U-Boot and the environment.
1621
1622 - CFG_ENV_OFFSET:
1623
1624 Offset of environment data (variable area) to the
1625 beginning of flash memory; for instance, with bottom boot
1626 type flash chips the second sector can be used: the offset
1627 for this sector is given here.
1628
1629 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1630
1631 - CFG_ENV_ADDR:
1632
1633 This is just another way to specify the start address of
1634 the flash sector containing the environment (instead of
1635 CFG_ENV_OFFSET).
1636
1637 - CFG_ENV_SECT_SIZE:
1638
1639 Size of the sector containing the environment.
1640
1641
1642 b) Sometimes flash chips have few, equal sized, BIG sectors.
1643 In such a case you don't want to spend a whole sector for
1644 the environment.
1645
1646 - CFG_ENV_SIZE:
1647
1648 If you use this in combination with CFG_ENV_IS_IN_FLASH
1649 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1650 of this flash sector for the environment. This saves
1651 memory for the RAM copy of the environment.
1652
1653 It may also save flash memory if you decide to use this
1654 when your environment is "embedded" within U-Boot code,
1655 since then the remainder of the flash sector could be used
1656 for U-Boot code. It should be pointed out that this is
1657 STRONGLY DISCOURAGED from a robustness point of view:
1658 updating the environment in flash makes it always
1659 necessary to erase the WHOLE sector. If something goes
1660 wrong before the contents has been restored from a copy in
1661 RAM, your target system will be dead.
1662
1663 - CFG_ENV_ADDR_REDUND
1664 CFG_ENV_SIZE_REDUND
1665
1666 These settings describe a second storage area used to hold
1667 a redundand copy of the environment data, so that there is
1668 a valid backup copy in case there is a power failure during
1669 a "saveenv" operation.
1670
1671 BE CAREFUL! Any changes to the flash layout, and some changes to the
1672 source code will make it necessary to adapt <board>/u-boot.lds*
1673 accordingly!
1674
1675
1676 - CFG_ENV_IS_IN_NVRAM:
1677
1678 Define this if you have some non-volatile memory device
1679 (NVRAM, battery buffered SRAM) which you want to use for the
1680 environment.
1681
1682 - CFG_ENV_ADDR:
1683 - CFG_ENV_SIZE:
1684
1685 These two #defines are used to determin the memory area you
1686 want to use for environment. It is assumed that this memory
1687 can just be read and written to, without any special
1688 provision.
1689
1690 BE CAREFUL! The first access to the environment happens quite early
1691 in U-Boot initalization (when we try to get the setting of for the
1692 console baudrate). You *MUST* have mappend your NVRAM area then, or
1693 U-Boot will hang.
1694
1695 Please note that even with NVRAM we still use a copy of the
1696 environment in RAM: we could work on NVRAM directly, but we want to
1697 keep settings there always unmodified except somebody uses "saveenv"
1698 to save the current settings.
1699
1700
1701 - CFG_ENV_IS_IN_EEPROM:
1702
1703 Use this if you have an EEPROM or similar serial access
1704 device and a driver for it.
1705
1706 - CFG_ENV_OFFSET:
1707 - CFG_ENV_SIZE:
1708
1709 These two #defines specify the offset and size of the
1710 environment area within the total memory of your EEPROM.
1711
1712 - CFG_I2C_EEPROM_ADDR:
1713 If defined, specified the chip address of the EEPROM device.
1714 The default address is zero.
1715
1716 - CFG_EEPROM_PAGE_WRITE_BITS:
1717 If defined, the number of bits used to address bytes in a
1718 single page in the EEPROM device. A 64 byte page, for example
1719 would require six bits.
1720
1721 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1722 If defined, the number of milliseconds to delay between
1723 page writes. The default is zero milliseconds.
1724
1725 - CFG_I2C_EEPROM_ADDR_LEN:
1726 The length in bytes of the EEPROM memory array address. Note
1727 that this is NOT the chip address length!
1728
1729 - CFG_EEPROM_SIZE:
1730 The size in bytes of the EEPROM device.
1731
1732
1733 - CFG_SPI_INIT_OFFSET
1734
1735 Defines offset to the initial SPI buffer area in DPRAM. The
1736 area is used at an early stage (ROM part) if the environment
1737 is configured to reside in the SPI EEPROM: We need a 520 byte
1738 scratch DPRAM area. It is used between the two initialization
1739 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1740 to be a good choice since it makes it far enough from the
1741 start of the data area as well as from the stack pointer.
1742
1743 Please note that the environment is read-only as long as the monitor
1744 has been relocated to RAM and a RAM copy of the environment has been
1745 created; also, when using EEPROM you will have to use getenv_r()
1746 until then to read environment variables.
1747
1748 The environment is protected by a CRC32 checksum. Before the monitor
1749 is relocated into RAM, as a result of a bad CRC you will be working
1750 with the compiled-in default environment - *silently*!!! [This is
1751 necessary, because the first environment variable we need is the
1752 "baudrate" setting for the console - if we have a bad CRC, we don't
1753 have any device yet where we could complain.]
1754
1755 Note: once the monitor has been relocated, then it will complain if
1756 the default environment is used; a new CRC is computed as soon as you
1757 use the "saveenv" command to store a valid environment.
1758
1759 - CFG_FAULT_ECHO_LINK_DOWN:
1760 Echo the inverted Ethernet link state to the fault LED.
1761
1762 Note: If this option is active, then CFG_FAULT_MII_ADDR
1763 also needs to be defined.
1764
1765 - CFG_FAULT_MII_ADDR:
1766 MII address of the PHY to check for the Ethernet link state.
1767
1768 Low Level (hardware related) configuration options:
1769 ---------------------------------------------------
1770
1771 - CFG_CACHELINE_SIZE:
1772 Cache Line Size of the CPU.
1773
1774 - CFG_DEFAULT_IMMR:
1775 Default address of the IMMR after system reset.
1776
1777 Needed on some 8260 systems (MPC8260ADS, PQ2FADS-ZU,
1778 and RPXsuper) to be able to adjust the position of
1779 the IMMR register after a reset.
1780
1781 - Floppy Disk Support:
1782 CFG_FDC_DRIVE_NUMBER
1783
1784 the default drive number (default value 0)
1785
1786 CFG_ISA_IO_STRIDE
1787
1788 defines the spacing between fdc chipset registers
1789 (default value 1)
1790
1791 CFG_ISA_IO_OFFSET
1792
1793 defines the offset of register from address. It
1794 depends on which part of the data bus is connected to
1795 the fdc chipset. (default value 0)
1796
1797 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1798 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1799 default value.
1800
1801 if CFG_FDC_HW_INIT is defined, then the function
1802 fdc_hw_init() is called at the beginning of the FDC
1803 setup. fdc_hw_init() must be provided by the board
1804 source code. It is used to make hardware dependant
1805 initializations.
1806
1807 - CFG_IMMR: Physical address of the Internal Memory Mapped
1808 Register; DO NOT CHANGE! (11-4)
1809 [MPC8xx systems only]
1810
1811 - CFG_INIT_RAM_ADDR:
1812
1813 Start address of memory area that can be used for
1814 initial data and stack; please note that this must be
1815 writable memory that is working WITHOUT special
1816 initialization, i. e. you CANNOT use normal RAM which
1817 will become available only after programming the
1818 memory controller and running certain initialization
1819 sequences.
1820
1821 U-Boot uses the following memory types:
1822 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1823 - MPC824X: data cache
1824 - PPC4xx: data cache
1825
1826 - CFG_GBL_DATA_OFFSET:
1827
1828 Offset of the initial data structure in the memory
1829 area defined by CFG_INIT_RAM_ADDR. Usually
1830 CFG_GBL_DATA_OFFSET is chosen such that the initial
1831 data is located at the end of the available space
1832 (sometimes written as (CFG_INIT_RAM_END -
1833 CFG_INIT_DATA_SIZE), and the initial stack is just
1834 below that area (growing from (CFG_INIT_RAM_ADDR +
1835 CFG_GBL_DATA_OFFSET) downward.
1836
1837 Note:
1838 On the MPC824X (or other systems that use the data
1839 cache for initial memory) the address chosen for
1840 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1841 point to an otherwise UNUSED address space between
1842 the top of RAM and the start of the PCI space.
1843
1844 - CFG_SIUMCR: SIU Module Configuration (11-6)
1845
1846 - CFG_SYPCR: System Protection Control (11-9)
1847
1848 - CFG_TBSCR: Time Base Status and Control (11-26)
1849
1850 - CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1851
1852 - CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1853
1854 - CFG_SCCR: System Clock and reset Control Register (15-27)
1855
1856 - CFG_OR_TIMING_SDRAM:
1857 SDRAM timing
1858
1859 - CFG_MAMR_PTA:
1860 periodic timer for refresh
1861
1862 - CFG_DER: Debug Event Register (37-47)
1863
1864 - FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1865 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1866 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1867 CFG_BR1_PRELIM:
1868 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1869
1870 - SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1871 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1872 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1873 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1874
1875 - CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1876 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1877 Machine Mode Register and Memory Periodic Timer
1878 Prescaler definitions (SDRAM timing)
1879
1880 - CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1881 enable I2C microcode relocation patch (MPC8xx);
1882 define relocation offset in DPRAM [DSP2]
1883
1884 - CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1885 enable SPI microcode relocation patch (MPC8xx);
1886 define relocation offset in DPRAM [SCC4]
1887
1888 - CFG_USE_OSCCLK:
1889 Use OSCM clock mode on MBX8xx board. Be careful,
1890 wrong setting might damage your board. Read
1891 doc/README.MBX before setting this variable!
1892
1893 - CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1894 Offset of the bootmode word in DPRAM used by post
1895 (Power On Self Tests). This definition overrides
1896 #define'd default value in commproc.h resp.
1897 cpm_8260.h.
1898
1899 - CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1900 CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1901 CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1902 CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1903 CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1904 CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1905 CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1906 CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1907 Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1908
1909 Building the Software:
1910 ======================
1911
1912 Building U-Boot has been tested in native PPC environments (on a
1913 PowerBook G3 running LinuxPPC 2000) and in cross environments
1914 (running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1915 NetBSD 1.5 on x86).
1916
1917 If you are not using a native PPC environment, it is assumed that you
1918 have the GNU cross compiling tools available in your path and named
1919 with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1920 you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1921 the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1922 change it to:
1923
1924 CROSS_COMPILE = ppc_4xx-
1925
1926
1927 U-Boot is intended to be simple to build. After installing the
1928 sources you must configure U-Boot for one specific board type. This
1929 is done by typing:
1930
1931 make NAME_config
1932
1933 where "NAME_config" is the name of one of the existing
1934 configurations; the following names are supported:
1935
1936 ADCIOP_config GTH_config TQM850L_config
1937 ADS860_config IP860_config TQM855L_config
1938 AR405_config IVML24_config TQM860L_config
1939 CANBT_config IVMS8_config WALNUT405_config
1940 CPCI405_config LANTEC_config cogent_common_config
1941 CPCIISER4_config MBX_config cogent_mpc8260_config
1942 CU824_config MBX860T_config cogent_mpc8xx_config
1943 ESTEEM192E_config RPXlite_config hermes_config
1944 ETX094_config RPXsuper_config hymod_config
1945 FADS823_config SM850_config lwmon_config
1946 FADS850SAR_config SPD823TS_config pcu_e_config
1947 FADS860T_config SXNI855T_config rsdproto_config
1948 FPS850L_config Sandpoint8240_config sbc8260_config
1949 GENIETV_config TQM823L_config PIP405_config
1950 GEN860T_config EBONY_config FPS860L_config
1951 ELPT860_config cmi_mpc5xx_config NETVIA_config
1952 at91rm9200dk_config omap1510inn_config MPC8260ADS_config
1953 omap1610inn_config ZPC1900_config
1954
1955 Note: for some board special configuration names may exist; check if
1956 additional information is available from the board vendor; for
1957 instance, the TQM8xxL systems run normally at 50 MHz and use a
1958 SCC for 10baseT ethernet; there are also systems with 80 MHz
1959 CPU clock, and an optional Fast Ethernet module is available
1960 for CPU's with FEC. You can select such additional "features"
1961 when chosing the configuration, i. e.
1962
1963 make TQM860L_config
1964 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1965
1966 make TQM860L_FEC_config
1967 - will configure for a TQM860L at 50MHz with FEC for ethernet
1968
1969 make TQM860L_80MHz_config
1970 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1971 interface
1972
1973 make TQM860L_FEC_80MHz_config
1974 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1975
1976 make TQM823L_LCD_config
1977 - will configure for a TQM823L with U-Boot console on LCD
1978
1979 make TQM823L_LCD_80MHz_config
1980 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1981
1982 etc.
1983
1984
1985 Finally, type "make all", and you should get some working U-Boot
1986 images ready for download to / installation on your system:
1987
1988 - "u-boot.bin" is a raw binary image
1989 - "u-boot" is an image in ELF binary format
1990 - "u-boot.srec" is in Motorola S-Record format
1991
1992
1993 Please be aware that the Makefiles assume you are using GNU make, so
1994 for instance on NetBSD you might need to use "gmake" instead of
1995 native "make".
1996
1997
1998 If the system board that you have is not listed, then you will need
1999 to port U-Boot to your hardware platform. To do this, follow these
2000 steps:
2001
2002 1. Add a new configuration option for your board to the toplevel
2003 "Makefile" and to the "MAKEALL" script, using the existing
2004 entries as examples. Note that here and at many other places
2005 boards and other names are listed in alphabetical sort order. Please
2006 keep this order.
2007 2. Create a new directory to hold your board specific code. Add any
2008 files you need. In your board directory, you will need at least
2009 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
2010 3. Create a new configuration file "include/configs/<board>.h" for
2011 your board
2012 3. If you're porting U-Boot to a new CPU, then also create a new
2013 directory to hold your CPU specific code. Add any files you need.
2014 4. Run "make <board>_config" with your new name.
2015 5. Type "make", and you should get a working "u-boot.srec" file
2016 to be installed on your target system.
2017 6. Debug and solve any problems that might arise.
2018 [Of course, this last step is much harder than it sounds.]
2019
2020
2021 Testing of U-Boot Modifications, Ports to New Hardware, etc.:
2022 ==============================================================
2023
2024 If you have modified U-Boot sources (for instance added a new board
2025 or support for new devices, a new CPU, etc.) you are expected to
2026 provide feedback to the other developers. The feedback normally takes
2027 the form of a "patch", i. e. a context diff against a certain (latest
2028 official or latest in CVS) version of U-Boot sources.
2029
2030 But before you submit such a patch, please verify that your modifi-
2031 cation did not break existing code. At least make sure that *ALL* of
2032 the supported boards compile WITHOUT ANY compiler warnings. To do so,
2033 just run the "MAKEALL" script, which will configure and build U-Boot
2034 for ALL supported system. Be warned, this will take a while. You can
2035 select which (cross) compiler to use by passing a `CROSS_COMPILE'
2036 environment variable to the script, i. e. to use the cross tools from
2037 MontaVista's Hard Hat Linux you can type
2038
2039 CROSS_COMPILE=ppc_8xx- MAKEALL
2040
2041 or to build on a native PowerPC system you can type
2042
2043 CROSS_COMPILE=' ' MAKEALL
2044
2045 See also "U-Boot Porting Guide" below.
2046
2047
2048 Monitor Commands - Overview:
2049 ============================
2050
2051 go - start application at address 'addr'
2052 run - run commands in an environment variable
2053 bootm - boot application image from memory
2054 bootp - boot image via network using BootP/TFTP protocol
2055 tftpboot- boot image via network using TFTP protocol
2056 and env variables "ipaddr" and "serverip"
2057 (and eventually "gatewayip")
2058 rarpboot- boot image via network using RARP/TFTP protocol
2059 diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
2060 loads - load S-Record file over serial line
2061 loadb - load binary file over serial line (kermit mode)
2062 md - memory display
2063 mm - memory modify (auto-incrementing)
2064 nm - memory modify (constant address)
2065 mw - memory write (fill)
2066 cp - memory copy
2067 cmp - memory compare
2068 crc32 - checksum calculation
2069 imd - i2c memory display
2070 imm - i2c memory modify (auto-incrementing)
2071 inm - i2c memory modify (constant address)
2072 imw - i2c memory write (fill)
2073 icrc32 - i2c checksum calculation
2074 iprobe - probe to discover valid I2C chip addresses
2075 iloop - infinite loop on address range
2076 isdram - print SDRAM configuration information
2077 sspi - SPI utility commands
2078 base - print or set address offset
2079 printenv- print environment variables
2080 setenv - set environment variables
2081 saveenv - save environment variables to persistent storage
2082 protect - enable or disable FLASH write protection
2083 erase - erase FLASH memory
2084 flinfo - print FLASH memory information
2085 bdinfo - print Board Info structure
2086 iminfo - print header information for application image
2087 coninfo - print console devices and informations
2088 ide - IDE sub-system
2089 loop - infinite loop on address range
2090 mtest - simple RAM test
2091 icache - enable or disable instruction cache
2092 dcache - enable or disable data cache
2093 reset - Perform RESET of the CPU
2094 echo - echo args to console
2095 version - print monitor version
2096 help - print online help
2097 ? - alias for 'help'
2098
2099
2100 Monitor Commands - Detailed Description:
2101 ========================================
2102
2103 TODO.
2104
2105 For now: just type "help <command>".
2106
2107
2108 Environment Variables:
2109 ======================
2110
2111 U-Boot supports user configuration using Environment Variables which
2112 can be made persistent by saving to Flash memory.
2113
2114 Environment Variables are set using "setenv", printed using
2115 "printenv", and saved to Flash using "saveenv". Using "setenv"
2116 without a value can be used to delete a variable from the
2117 environment. As long as you don't save the environment you are
2118 working with an in-memory copy. In case the Flash area containing the
2119 environment is erased by accident, a default environment is provided.
2120
2121 Some configuration options can be set using Environment Variables:
2122
2123 baudrate - see CONFIG_BAUDRATE
2124
2125 bootdelay - see CONFIG_BOOTDELAY
2126
2127 bootcmd - see CONFIG_BOOTCOMMAND
2128
2129 bootargs - Boot arguments when booting an RTOS image
2130
2131 bootfile - Name of the image to load with TFTP
2132
2133 autoload - if set to "no" (any string beginning with 'n'),
2134 "bootp" will just load perform a lookup of the
2135 configuration from the BOOTP server, but not try to
2136 load any image using TFTP
2137
2138 autostart - if set to "yes", an image loaded using the "bootp",
2139 "rarpboot", "tftpboot" or "diskboot" commands will
2140 be automatically started (by internally calling
2141 "bootm")
2142
2143 If set to "no", a standalone image passed to the
2144 "bootm" command will be copied to the load address
2145 (and eventually uncompressed), but NOT be started.
2146 This can be used to load and uncompress arbitrary
2147 data.
2148
2149 initrd_high - restrict positioning of initrd images:
2150 If this variable is not set, initrd images will be
2151 copied to the highest possible address in RAM; this
2152 is usually what you want since it allows for
2153 maximum initrd size. If for some reason you want to
2154 make sure that the initrd image is loaded below the
2155 CFG_BOOTMAPSZ limit, you can set this environment
2156 variable to a value of "no" or "off" or "0".
2157 Alternatively, you can set it to a maximum upper
2158 address to use (U-Boot will still check that it
2159 does not overwrite the U-Boot stack and data).
2160
2161 For instance, when you have a system with 16 MB
2162 RAM, and want to reserve 4 MB from use by Linux,
2163 you can do this by adding "mem=12M" to the value of
2164 the "bootargs" variable. However, now you must make
2165 sure that the initrd image is placed in the first
2166 12 MB as well - this can be done with
2167
2168 setenv initrd_high 00c00000
2169
2170 If you set initrd_high to 0xFFFFFFFF, this is an
2171 indication to U-Boot that all addresses are legal
2172 for the Linux kernel, including addresses in flash
2173 memory. In this case U-Boot will NOT COPY the
2174 ramdisk at all. This may be useful to reduce the
2175 boot time on your system, but requires that this
2176 feature is supported by your Linux kernel.
2177
2178 ipaddr - IP address; needed for tftpboot command
2179
2180 loadaddr - Default load address for commands like "bootp",
2181 "rarpboot", "tftpboot", "loadb" or "diskboot"
2182
2183 loads_echo - see CONFIG_LOADS_ECHO
2184
2185 serverip - TFTP server IP address; needed for tftpboot command
2186
2187 bootretry - see CONFIG_BOOT_RETRY_TIME
2188
2189 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
2190
2191 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
2192
2193
2194 The following environment variables may be used and automatically
2195 updated by the network boot commands ("bootp" and "rarpboot"),
2196 depending the information provided by your boot server:
2197
2198 bootfile - see above
2199 dnsip - IP address of your Domain Name Server
2200 dnsip2 - IP address of your secondary Domain Name Server
2201 gatewayip - IP address of the Gateway (Router) to use
2202 hostname - Target hostname
2203 ipaddr - see above
2204 netmask - Subnet Mask
2205 rootpath - Pathname of the root filesystem on the NFS server
2206 serverip - see above
2207
2208
2209 There are two special Environment Variables:
2210
2211 serial# - contains hardware identification information such
2212 as type string and/or serial number
2213 ethaddr - Ethernet address
2214
2215 These variables can be set only once (usually during manufacturing of
2216 the board). U-Boot refuses to delete or overwrite these variables
2217 once they have been set once.
2218
2219
2220 Further special Environment Variables:
2221
2222 ver - Contains the U-Boot version string as printed
2223 with the "version" command. This variable is
2224 readonly (see CONFIG_VERSION_VARIABLE).
2225
2226
2227 Please note that changes to some configuration parameters may take
2228 only effect after the next boot (yes, that's just like Windoze :-).
2229
2230
2231 Command Line Parsing:
2232 =====================
2233
2234 There are two different command line parsers available with U-Boot:
2235 the old "simple" one, and the much more powerful "hush" shell:
2236
2237 Old, simple command line parser:
2238 --------------------------------
2239
2240 - supports environment variables (through setenv / saveenv commands)
2241 - several commands on one line, separated by ';'
2242 - variable substitution using "... $(name) ..." syntax
2243 - special characters ('$', ';') can be escaped by prefixing with '\',
2244 for example:
2245 setenv bootcmd bootm \$(address)
2246 - You can also escape text by enclosing in single apostrophes, for example:
2247 setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2248
2249 Hush shell:
2250 -----------
2251
2252 - similar to Bourne shell, with control structures like
2253 if...then...else...fi, for...do...done; while...do...done,
2254 until...do...done, ...
2255 - supports environment ("global") variables (through setenv / saveenv
2256 commands) and local shell variables (through standard shell syntax
2257 "name=value"); only environment variables can be used with "run"
2258 command
2259
2260 General rules:
2261 --------------
2262
2263 (1) If a command line (or an environment variable executed by a "run"
2264 command) contains several commands separated by semicolon, and
2265 one of these commands fails, then the remaining commands will be
2266 executed anyway.
2267
2268 (2) If you execute several variables with one call to run (i. e.
2269 calling run with a list af variables as arguments), any failing
2270 command will cause "run" to terminate, i. e. the remaining
2271 variables are not executed.
2272
2273 Note for Redundant Ethernet Interfaces:
2274 =======================================
2275
2276 Some boards come with redundant ethernet interfaces; U-Boot supports
2277 such configurations and is capable of automatic selection of a
2278 "working" interface when needed. MAC assignment works as follows:
2279
2280 Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2281 MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2282 "eth1addr" (=>eth1), "eth2addr", ...
2283
2284 If the network interface stores some valid MAC address (for instance
2285 in SROM), this is used as default address if there is NO correspon-
2286 ding setting in the environment; if the corresponding environment
2287 variable is set, this overrides the settings in the card; that means:
2288
2289 o If the SROM has a valid MAC address, and there is no address in the
2290 environment, the SROM's address is used.
2291
2292 o If there is no valid address in the SROM, and a definition in the
2293 environment exists, then the value from the environment variable is
2294 used.
2295
2296 o If both the SROM and the environment contain a MAC address, and
2297 both addresses are the same, this MAC address is used.
2298
2299 o If both the SROM and the environment contain a MAC address, and the
2300 addresses differ, the value from the environment is used and a
2301 warning is printed.
2302
2303 o If neither SROM nor the environment contain a MAC address, an error
2304 is raised.
2305
2306
2307 Image Formats:
2308 ==============
2309
2310 The "boot" commands of this monitor operate on "image" files which
2311 can be basicly anything, preceeded by a special header; see the
2312 definitions in include/image.h for details; basicly, the header
2313 defines the following image properties:
2314
2315 * Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2316 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2317 LynxOS, pSOS, QNX, RTEMS, ARTOS;
2318 Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS, LynxOS).
2319 * Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2320 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2321 Currently supported: PowerPC).
2322 * Compression Type (uncompressed, gzip, bzip2)
2323 * Load Address
2324 * Entry Point
2325 * Image Name
2326 * Image Timestamp
2327
2328 The header is marked by a special Magic Number, and both the header
2329 and the data portions of the image are secured against corruption by
2330 CRC32 checksums.
2331
2332
2333 Linux Support:
2334 ==============
2335
2336 Although U-Boot should support any OS or standalone application
2337 easily, the main focus has always been on Linux during the design of
2338 U-Boot.
2339
2340 U-Boot includes many features that so far have been part of some
2341 special "boot loader" code within the Linux kernel. Also, any
2342 "initrd" images to be used are no longer part of one big Linux image;
2343 instead, kernel and "initrd" are separate images. This implementation
2344 serves several purposes:
2345
2346 - the same features can be used for other OS or standalone
2347 applications (for instance: using compressed images to reduce the
2348 Flash memory footprint)
2349
2350 - it becomes much easier to port new Linux kernel versions because
2351 lots of low-level, hardware dependent stuff are done by U-Boot
2352
2353 - the same Linux kernel image can now be used with different "initrd"
2354 images; of course this also means that different kernel images can
2355 be run with the same "initrd". This makes testing easier (you don't
2356 have to build a new "zImage.initrd" Linux image when you just
2357 change a file in your "initrd"). Also, a field-upgrade of the
2358 software is easier now.
2359
2360
2361 Linux HOWTO:
2362 ============
2363
2364 Porting Linux to U-Boot based systems:
2365 ---------------------------------------
2366
2367 U-Boot cannot save you from doing all the necessary modifications to
2368 configure the Linux device drivers for use with your target hardware
2369 (no, we don't intend to provide a full virtual machine interface to
2370 Linux :-).
2371
2372 But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2373
2374 Just make sure your machine specific header file (for instance
2375 include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2376 Information structure as we define in include/u-boot.h, and make
2377 sure that your definition of IMAP_ADDR uses the same value as your
2378 U-Boot configuration in CFG_IMMR.
2379
2380
2381 Configuring the Linux kernel:
2382 -----------------------------
2383
2384 No specific requirements for U-Boot. Make sure you have some root
2385 device (initial ramdisk, NFS) for your target system.
2386
2387
2388 Building a Linux Image:
2389 -----------------------
2390
2391 With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2392 not used. If you use recent kernel source, a new build target
2393 "uImage" will exist which automatically builds an image usable by
2394 U-Boot. Most older kernels also have support for a "pImage" target,
2395 which was introduced for our predecessor project PPCBoot and uses a
2396 100% compatible format.
2397
2398 Example:
2399
2400 make TQM850L_config
2401 make oldconfig
2402 make dep
2403 make uImage
2404
2405 The "uImage" build target uses a special tool (in 'tools/mkimage') to
2406 encapsulate a compressed Linux kernel image with header information,
2407 CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2408
2409 * build a standard "vmlinux" kernel image (in ELF binary format):
2410
2411 * convert the kernel into a raw binary image:
2412
2413 ${CROSS_COMPILE}-objcopy -O binary \
2414 -R .note -R .comment \
2415 -S vmlinux linux.bin
2416
2417 * compress the binary image:
2418
2419 gzip -9 linux.bin
2420
2421 * package compressed binary image for U-Boot:
2422
2423 mkimage -A ppc -O linux -T kernel -C gzip \
2424 -a 0 -e 0 -n "Linux Kernel Image" \
2425 -d linux.bin.gz uImage
2426
2427
2428 The "mkimage" tool can also be used to create ramdisk images for use
2429 with U-Boot, either separated from the Linux kernel image, or
2430 combined into one file. "mkimage" encapsulates the images with a 64
2431 byte header containing information about target architecture,
2432 operating system, image type, compression method, entry points, time
2433 stamp, CRC32 checksums, etc.
2434
2435 "mkimage" can be called in two ways: to verify existing images and
2436 print the header information, or to build new images.
2437
2438 In the first form (with "-l" option) mkimage lists the information
2439 contained in the header of an existing U-Boot image; this includes
2440 checksum verification:
2441
2442 tools/mkimage -l image
2443 -l ==> list image header information
2444
2445 The second form (with "-d" option) is used to build a U-Boot image
2446 from a "data file" which is used as image payload:
2447
2448 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2449 -n name -d data_file image
2450 -A ==> set architecture to 'arch'
2451 -O ==> set operating system to 'os'
2452 -T ==> set image type to 'type'
2453 -C ==> set compression type 'comp'
2454 -a ==> set load address to 'addr' (hex)
2455 -e ==> set entry point to 'ep' (hex)
2456 -n ==> set image name to 'name'
2457 -d ==> use image data from 'datafile'
2458
2459 Right now, all Linux kernels use the same load address (0x00000000),
2460 but the entry point address depends on the kernel version:
2461
2462 - 2.2.x kernels have the entry point at 0x0000000C,
2463 - 2.3.x and later kernels have the entry point at 0x00000000.
2464
2465 So a typical call to build a U-Boot image would read:
2466
2467 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2468 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2469 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2470 > examples/uImage.TQM850L
2471 Image Name: 2.4.4 kernel for TQM850L
2472 Created: Wed Jul 19 02:34:59 2000
2473 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2474 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2475 Load Address: 0x00000000
2476 Entry Point: 0x00000000
2477
2478 To verify the contents of the image (or check for corruption):
2479
2480 -> tools/mkimage -l examples/uImage.TQM850L
2481 Image Name: 2.4.4 kernel for TQM850L
2482 Created: Wed Jul 19 02:34:59 2000
2483 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2484 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2485 Load Address: 0x00000000
2486 Entry Point: 0x00000000
2487
2488 NOTE: for embedded systems where boot time is critical you can trade
2489 speed for memory and install an UNCOMPRESSED image instead: this
2490 needs more space in Flash, but boots much faster since it does not
2491 need to be uncompressed:
2492
2493 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2494 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2495 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2496 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2497 > examples/uImage.TQM850L-uncompressed
2498 Image Name: 2.4.4 kernel for TQM850L
2499 Created: Wed Jul 19 02:34:59 2000
2500 Image Type: PowerPC Linux Kernel Image (uncompressed)
2501 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2502 Load Address: 0x00000000
2503 Entry Point: 0x00000000
2504
2505
2506 Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2507 when your kernel is intended to use an initial ramdisk:
2508
2509 -> tools/mkimage -n 'Simple Ramdisk Image' \
2510 > -A ppc -O linux -T ramdisk -C gzip \
2511 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2512 Image Name: Simple Ramdisk Image
2513 Created: Wed Jan 12 14:01:50 2000
2514 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2515 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2516 Load Address: 0x00000000
2517 Entry Point: 0x00000000
2518
2519
2520 Installing a Linux Image:
2521 -------------------------
2522
2523 To downloading a U-Boot image over the serial (console) interface,
2524 you must convert the image to S-Record format:
2525
2526 objcopy -I binary -O srec examples/image examples/image.srec
2527
2528 The 'objcopy' does not understand the information in the U-Boot
2529 image header, so the resulting S-Record file will be relative to
2530 address 0x00000000. To load it to a given address, you need to
2531 specify the target address as 'offset' parameter with the 'loads'
2532 command.
2533
2534 Example: install the image to address 0x40100000 (which on the
2535 TQM8xxL is in the first Flash bank):
2536
2537 => erase 40100000 401FFFFF
2538
2539 .......... done
2540 Erased 8 sectors
2541
2542 => loads 40100000
2543 ## Ready for S-Record download ...
2544 ~>examples/image.srec
2545 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2546 ...
2547 15989 15990 15991 15992
2548 [file transfer complete]
2549 [connected]
2550 ## Start Addr = 0x00000000
2551
2552
2553 You can check the success of the download using the 'iminfo' command;
2554 this includes a checksum verification so you can be sure no data
2555 corruption happened:
2556
2557 => imi 40100000
2558
2559 ## Checking Image at 40100000 ...
2560 Image Name: 2.2.13 for initrd on TQM850L
2561 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2562 Data Size: 335725 Bytes = 327 kB = 0 MB
2563 Load Address: 00000000
2564 Entry Point: 0000000c
2565 Verifying Checksum ... OK
2566
2567
2568 Boot Linux:
2569 -----------
2570
2571 The "bootm" command is used to boot an application that is stored in
2572 memory (RAM or Flash). In case of a Linux kernel image, the contents
2573 of the "bootargs" environment variable is passed to the kernel as
2574 parameters. You can check and modify this variable using the
2575 "printenv" and "setenv" commands:
2576
2577
2578 => printenv bootargs
2579 bootargs=root=/dev/ram
2580
2581 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2582
2583 => printenv bootargs
2584 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2585
2586 => bootm 40020000
2587 ## Booting Linux kernel at 40020000 ...
2588 Image Name: 2.2.13 for NFS on TQM850L
2589 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2590 Data Size: 381681 Bytes = 372 kB = 0 MB
2591 Load Address: 00000000
2592 Entry Point: 0000000c
2593 Verifying Checksum ... OK
2594 Uncompressing Kernel Image ... OK
2595 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
2596 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2597 time_init: decrementer frequency = 187500000/60
2598 Calibrating delay loop... 49.77 BogoMIPS
2599 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2600 ...
2601
2602 If you want to boot a Linux kernel with initial ram disk, you pass
2603 the memory addresses of both the kernel and the initrd image (PPBCOOT
2604 format!) to the "bootm" command:
2605
2606 => imi 40100000 40200000
2607
2608 ## Checking Image at 40100000 ...
2609 Image Name: 2.2.13 for initrd on TQM850L
2610 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2611 Data Size: 335725 Bytes = 327 kB = 0 MB
2612 Load Address: 00000000
2613 Entry Point: 0000000c
2614 Verifying Checksum ... OK
2615
2616 ## Checking Image at 40200000 ...
2617 Image Name: Simple Ramdisk Image
2618 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2619 Data Size: 566530 Bytes = 553 kB = 0 MB
2620 Load Address: 00000000
2621 Entry Point: 00000000
2622 Verifying Checksum ... OK
2623
2624 => bootm 40100000 40200000
2625 ## Booting Linux kernel at 40100000 ...
2626 Image Name: 2.2.13 for initrd on TQM850L
2627 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2628 Data Size: 335725 Bytes = 327 kB = 0 MB
2629 Load Address: 00000000
2630 Entry Point: 0000000c
2631 Verifying Checksum ... OK
2632 Uncompressing Kernel Image ... OK
2633 ## Loading RAMDisk Image at 40200000 ...
2634 Image Name: Simple Ramdisk Image
2635 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2636 Data Size: 566530 Bytes = 553 kB = 0 MB
2637 Load Address: 00000000
2638 Entry Point: 00000000
2639 Verifying Checksum ... OK
2640 Loading Ramdisk ... OK
2641 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
2642 Boot arguments: root=/dev/ram
2643 time_init: decrementer frequency = 187500000/60
2644 Calibrating delay loop... 49.77 BogoMIPS
2645 ...
2646 RAMDISK: Compressed image found at block 0
2647 VFS: Mounted root (ext2 filesystem).
2648
2649 bash#
2650
2651 More About U-Boot Image Types:
2652 ------------------------------
2653
2654 U-Boot supports the following image types:
2655
2656 "Standalone Programs" are directly runnable in the environment
2657 provided by U-Boot; it is expected that (if they behave
2658 well) you can continue to work in U-Boot after return from
2659 the Standalone Program.
2660 "OS Kernel Images" are usually images of some Embedded OS which
2661 will take over control completely. Usually these programs
2662 will install their own set of exception handlers, device
2663 drivers, set up the MMU, etc. - this means, that you cannot
2664 expect to re-enter U-Boot except by resetting the CPU.
2665 "RAMDisk Images" are more or less just data blocks, and their
2666 parameters (address, size) are passed to an OS kernel that is
2667 being started.
2668 "Multi-File Images" contain several images, typically an OS
2669 (Linux) kernel image and one or more data images like
2670 RAMDisks. This construct is useful for instance when you want
2671 to boot over the network using BOOTP etc., where the boot
2672 server provides just a single image file, but you want to get
2673 for instance an OS kernel and a RAMDisk image.
2674
2675 "Multi-File Images" start with a list of image sizes, each
2676 image size (in bytes) specified by an "uint32_t" in network
2677 byte order. This list is terminated by an "(uint32_t)0".
2678 Immediately after the terminating 0 follow the images, one by
2679 one, all aligned on "uint32_t" boundaries (size rounded up to
2680 a multiple of 4 bytes).
2681
2682 "Firmware Images" are binary images containing firmware (like
2683 U-Boot or FPGA images) which usually will be programmed to
2684 flash memory.
2685
2686 "Script files" are command sequences that will be executed by
2687 U-Boot's command interpreter; this feature is especially
2688 useful when you configure U-Boot to use a real shell (hush)
2689 as command interpreter.
2690
2691
2692 Standalone HOWTO:
2693 =================
2694
2695 One of the features of U-Boot is that you can dynamically load and
2696 run "standalone" applications, which can use some resources of
2697 U-Boot like console I/O functions or interrupt services.
2698
2699 Two simple examples are included with the sources:
2700
2701 "Hello World" Demo:
2702 -------------------
2703
2704 'examples/hello_world.c' contains a small "Hello World" Demo
2705 application; it is automatically compiled when you build U-Boot.
2706 It's configured to run at address 0x00040004, so you can play with it
2707 like that:
2708
2709 => loads
2710 ## Ready for S-Record download ...
2711 ~>examples/hello_world.srec
2712 1 2 3 4 5 6 7 8 9 10 11 ...
2713 [file transfer complete]
2714 [connected]
2715 ## Start Addr = 0x00040004
2716
2717 => go 40004 Hello World! This is a test.
2718 ## Starting application at 0x00040004 ...
2719 Hello World
2720 argc = 7
2721 argv[0] = "40004"
2722 argv[1] = "Hello"
2723 argv[2] = "World!"
2724 argv[3] = "This"
2725 argv[4] = "is"
2726 argv[5] = "a"
2727 argv[6] = "test."
2728 argv[7] = "<NULL>"
2729 Hit any key to exit ...
2730
2731 ## Application terminated, rc = 0x0
2732
2733 Another example, which demonstrates how to register a CPM interrupt
2734 handler with the U-Boot code, can be found in 'examples/timer.c'.
2735 Here, a CPM timer is set up to generate an interrupt every second.
2736 The interrupt service routine is trivial, just printing a '.'
2737 character, but this is just a demo program. The application can be
2738 controlled by the following keys:
2739
2740 ? - print current values og the CPM Timer registers
2741 b - enable interrupts and start timer
2742 e - stop timer and disable interrupts
2743 q - quit application
2744
2745 => loads
2746 ## Ready for S-Record download ...
2747 ~>examples/timer.srec
2748 1 2 3 4 5 6 7 8 9 10 11 ...
2749 [file transfer complete]
2750 [connected]
2751 ## Start Addr = 0x00040004
2752
2753 => go 40004
2754 ## Starting application at 0x00040004 ...
2755 TIMERS=0xfff00980
2756 Using timer 1
2757 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2758
2759 Hit 'b':
2760 [q, b, e, ?] Set interval 1000000 us
2761 Enabling timer
2762 Hit '?':
2763 [q, b, e, ?] ........
2764 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2765 Hit '?':
2766 [q, b, e, ?] .
2767 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2768 Hit '?':
2769 [q, b, e, ?] .
2770 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2771 Hit '?':
2772 [q, b, e, ?] .
2773 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2774 Hit 'e':
2775 [q, b, e, ?] ...Stopping timer
2776 Hit 'q':
2777 [q, b, e, ?] ## Application terminated, rc = 0x0
2778
2779
2780 Minicom warning:
2781 ================
2782
2783 Over time, many people have reported problems when trying to use the
2784 "minicom" terminal emulation program for serial download. I (wd)
2785 consider minicom to be broken, and recommend not to use it. Under
2786 Unix, I recommend to use C-Kermit for general purpose use (and
2787 especially for kermit binary protocol download ("loadb" command), and
2788 use "cu" for S-Record download ("loads" command).
2789
2790 Nevertheless, if you absolutely want to use it try adding this
2791 configuration to your "File transfer protocols" section:
2792
2793 Name Program Name U/D FullScr IO-Red. Multi
2794 X kermit /usr/bin/kermit -i -l %l -s Y U Y N N
2795 Y kermit /usr/bin/kermit -i -l %l -r N D Y N N
2796
2797
2798 NetBSD Notes:
2799 =============
2800
2801 Starting at version 0.9.2, U-Boot supports NetBSD both as host
2802 (build U-Boot) and target system (boots NetBSD/mpc8xx).
2803
2804 Building requires a cross environment; it is known to work on
2805 NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2806 need gmake since the Makefiles are not compatible with BSD make).
2807 Note that the cross-powerpc package does not install include files;
2808 attempting to build U-Boot will fail because <machine/ansi.h> is
2809 missing. This file has to be installed and patched manually:
2810
2811 # cd /usr/pkg/cross/powerpc-netbsd/include
2812 # mkdir powerpc
2813 # ln -s powerpc machine
2814 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2815 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2816
2817 Native builds *don't* work due to incompatibilities between native
2818 and U-Boot include files.
2819
2820 Booting assumes that (the first part of) the image booted is a
2821 stage-2 loader which in turn loads and then invokes the kernel
2822 proper. Loader sources will eventually appear in the NetBSD source
2823 tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2824 meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2825 details.
2826
2827
2828 Implementation Internals:
2829 =========================
2830
2831 The following is not intended to be a complete description of every
2832 implementation detail. However, it should help to understand the
2833 inner workings of U-Boot and make it easier to port it to custom
2834 hardware.
2835
2836
2837 Initial Stack, Global Data:
2838 ---------------------------
2839
2840 The implementation of U-Boot is complicated by the fact that U-Boot
2841 starts running out of ROM (flash memory), usually without access to
2842 system RAM (because the memory controller is not initialized yet).
2843 This means that we don't have writable Data or BSS segments, and BSS
2844 is not initialized as zero. To be able to get a C environment working
2845 at all, we have to allocate at least a minimal stack. Implementation
2846 options for this are defined and restricted by the CPU used: Some CPU
2847 models provide on-chip memory (like the IMMR area on MPC8xx and
2848 MPC826x processors), on others (parts of) the data cache can be
2849 locked as (mis-) used as memory, etc.
2850
2851 Chris Hallinan posted a good summary of these issues to the
2852 u-boot-users mailing list:
2853
2854 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2855 From: "Chris Hallinan" <clh@net1plus.com>
2856 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2857 ...
2858
2859 Correct me if I'm wrong, folks, but the way I understand it
2860 is this: Using DCACHE as initial RAM for Stack, etc, does not
2861 require any physical RAM backing up the cache. The cleverness
2862 is that the cache is being used as a temporary supply of
2863 necessary storage before the SDRAM controller is setup. It's
2864 beyond the scope of this list to expain the details, but you
2865 can see how this works by studying the cache architecture and
2866 operation in the architecture and processor-specific manuals.
2867
2868 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2869 is another option for the system designer to use as an
2870 initial stack/ram area prior to SDRAM being available. Either
2871 option should work for you. Using CS 4 should be fine if your
2872 board designers haven't used it for something that would
2873 cause you grief during the initial boot! It is frequently not
2874 used.
2875
2876 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2877 with your processor/board/system design. The default value
2878 you will find in any recent u-boot distribution in
2879 Walnut405.h should work for you. I'd set it to a value larger
2880 than your SDRAM module. If you have a 64MB SDRAM module, set
2881 it above 400_0000. Just make sure your board has no resources
2882 that are supposed to respond to that address! That code in
2883 start.S has been around a while and should work as is when
2884 you get the config right.
2885
2886 -Chris Hallinan
2887 DS4.COM, Inc.
2888
2889 It is essential to remember this, since it has some impact on the C
2890 code for the initialization procedures:
2891
2892 * Initialized global data (data segment) is read-only. Do not attempt
2893 to write it.
2894
2895 * Do not use any unitialized global data (or implicitely initialized
2896 as zero data - BSS segment) at all - this is undefined, initiali-
2897 zation is performed later (when relocating to RAM).
2898
2899 * Stack space is very limited. Avoid big data buffers or things like
2900 that.
2901
2902 Having only the stack as writable memory limits means we cannot use
2903 normal global data to share information beween the code. But it
2904 turned out that the implementation of U-Boot can be greatly
2905 simplified by making a global data structure (gd_t) available to all
2906 functions. We could pass a pointer to this data as argument to _all_
2907 functions, but this would bloat the code. Instead we use a feature of
2908 the GCC compiler (Global Register Variables) to share the data: we
2909 place a pointer (gd) to the global data into a register which we
2910 reserve for this purpose.
2911
2912 When choosing a register for such a purpose we are restricted by the
2913 relevant (E)ABI specifications for the current architecture, and by
2914 GCC's implementation.
2915
2916 For PowerPC, the following registers have specific use:
2917 R1: stack pointer
2918 R2: TOC pointer
2919 R3-R4: parameter passing and return values
2920 R5-R10: parameter passing
2921 R13: small data area pointer
2922 R30: GOT pointer
2923 R31: frame pointer
2924
2925 (U-Boot also uses R14 as internal GOT pointer.)
2926
2927 ==> U-Boot will use R29 to hold a pointer to the global data
2928
2929 Note: on PPC, we could use a static initializer (since the
2930 address of the global data structure is known at compile time),
2931 but it turned out that reserving a register results in somewhat
2932 smaller code - although the code savings are not that big (on
2933 average for all boards 752 bytes for the whole U-Boot image,
2934 624 text + 127 data).
2935
2936 On ARM, the following registers are used:
2937
2938 R0: function argument word/integer result
2939 R1-R3: function argument word
2940 R9: GOT pointer
2941 R10: stack limit (used only if stack checking if enabled)
2942 R11: argument (frame) pointer
2943 R12: temporary workspace
2944 R13: stack pointer
2945 R14: link register
2946 R15: program counter
2947
2948 ==> U-Boot will use R8 to hold a pointer to the global data
2949
2950
2951 Memory Management:
2952 ------------------
2953
2954 U-Boot runs in system state and uses physical addresses, i.e. the
2955 MMU is not used either for address mapping nor for memory protection.
2956
2957 The available memory is mapped to fixed addresses using the memory
2958 controller. In this process, a contiguous block is formed for each
2959 memory type (Flash, SDRAM, SRAM), even when it consists of several
2960 physical memory banks.
2961
2962 U-Boot is installed in the first 128 kB of the first Flash bank (on
2963 TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2964 booting and sizing and initializing DRAM, the code relocates itself
2965 to the upper end of DRAM. Immediately below the U-Boot code some
2966 memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2967 configuration setting]. Below that, a structure with global Board
2968 Info data is placed, followed by the stack (growing downward).
2969
2970 Additionally, some exception handler code is copied to the low 8 kB
2971 of DRAM (0x00000000 ... 0x00001FFF).
2972
2973 So a typical memory configuration with 16 MB of DRAM could look like
2974 this:
2975
2976 0x0000 0000 Exception Vector code
2977 :
2978 0x0000 1FFF
2979 0x0000 2000 Free for Application Use
2980 :
2981 :
2982
2983 :
2984 :
2985 0x00FB FF20 Monitor Stack (Growing downward)
2986 0x00FB FFAC Board Info Data and permanent copy of global data
2987 0x00FC 0000 Malloc Arena
2988 :
2989 0x00FD FFFF
2990 0x00FE 0000 RAM Copy of Monitor Code
2991 ... eventually: LCD or video framebuffer
2992 ... eventually: pRAM (Protected RAM - unchanged by reset)
2993 0x00FF FFFF [End of RAM]
2994
2995
2996 System Initialization:
2997 ----------------------
2998
2999 In the reset configuration, U-Boot starts at the reset entry point
3000 (on most PowerPC systens at address 0x00000100). Because of the reset
3001 configuration for CS0# this is a mirror of the onboard Flash memory.
3002 To be able to re-map memory U-Boot then jumps to its link address.
3003 To be able to implement the initialization code in C, a (small!)
3004 initial stack is set up in the internal Dual Ported RAM (in case CPUs
3005 which provide such a feature like MPC8xx or MPC8260), or in a locked
3006 part of the data cache. After that, U-Boot initializes the CPU core,
3007 the caches and the SIU.
3008
3009 Next, all (potentially) available memory banks are mapped using a
3010 preliminary mapping. For example, we put them on 512 MB boundaries
3011 (multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
3012 on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
3013 programmed for SDRAM access. Using the temporary configuration, a
3014 simple memory test is run that determines the size of the SDRAM
3015 banks.
3016
3017 When there is more than one SDRAM bank, and the banks are of
3018 different size, the largest is mapped first. For equal size, the first
3019 bank (CS2#) is mapped first. The first mapping is always for address
3020 0x00000000, with any additional banks following immediately to create
3021 contiguous memory starting from 0.
3022
3023 Then, the monitor installs itself at the upper end of the SDRAM area
3024 and allocates memory for use by malloc() and for the global Board
3025 Info data; also, the exception vector code is copied to the low RAM
3026 pages, and the final stack is set up.
3027
3028 Only after this relocation will you have a "normal" C environment;
3029 until that you are restricted in several ways, mostly because you are
3030 running from ROM, and because the code will have to be relocated to a
3031 new address in RAM.
3032
3033
3034 U-Boot Porting Guide:
3035 ----------------------
3036
3037 [Based on messages by Jerry Van Baren in the U-Boot-Users mailing
3038 list, October 2002]
3039
3040
3041 int main (int argc, char *argv[])
3042 {
3043 sighandler_t no_more_time;
3044
3045 signal (SIGALRM, no_more_time);
3046 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
3047
3048 if (available_money > available_manpower) {
3049 pay consultant to port U-Boot;
3050 return 0;
3051 }
3052
3053 Download latest U-Boot source;
3054
3055 Subscribe to u-boot-users mailing list;
3056
3057 if (clueless) {
3058 email ("Hi, I am new to U-Boot, how do I get started?");
3059 }
3060
3061 while (learning) {
3062 Read the README file in the top level directory;
3063 Read http://www.denx.de/re/DPLG.html
3064 Read the source, Luke;
3065 }
3066
3067 if (available_money > toLocalCurrency ($2500)) {
3068 Buy a BDI2000;
3069 } else {
3070 Add a lot of aggravation and time;
3071 }
3072
3073 Create your own board support subdirectory;
3074
3075 Create your own board config file;
3076
3077 while (!running) {
3078 do {
3079 Add / modify source code;
3080 } until (compiles);
3081 Debug;
3082 if (clueless)
3083 email ("Hi, I am having problems...");
3084 }
3085 Send patch file to Wolfgang;
3086
3087 return 0;
3088 }
3089
3090 void no_more_time (int sig)
3091 {
3092 hire_a_guru();
3093 }
3094
3095
3096 Coding Standards:
3097 -----------------
3098
3099 All contributions to U-Boot should conform to the Linux kernel
3100 coding style; see the file "Documentation/CodingStyle" in your Linux
3101 kernel source directory.
3102
3103 Please note that U-Boot is implemented in C (and to some small parts
3104 in Assembler); no C++ is used, so please do not use C++ style
3105 comments (//) in your code.
3106
3107 Submissions which do not conform to the standards may be returned
3108 with a request to reformat the changes.
3109
3110
3111 Submitting Patches:
3112 -------------------
3113
3114 Since the number of patches for U-Boot is growing, we need to
3115 establish some rules. Submissions which do not conform to these rules
3116 may be rejected, even when they contain important and valuable stuff.
3117
3118
3119 When you send a patch, please include the following information with
3120 it:
3121
3122 * For bug fixes: a description of the bug and how your patch fixes
3123 this bug. Please try to include a way of demonstrating that the
3124 patch actually fixes something.
3125
3126 * For new features: a description of the feature and your
3127 implementation.
3128
3129 * A CHANGELOG entry as plaintext (separate from the patch)
3130
3131 * For major contributions, your entry to the CREDITS file
3132
3133 * When you add support for a new board, don't forget to add this
3134 board to the MAKEALL script, too.
3135
3136 * If your patch adds new configuration options, don't forget to
3137 document these in the README file.
3138
3139 * The patch itself. If you are accessing the CVS repository use "cvs
3140 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3141 version of diff does not support these options, then get the latest
3142 version of GNU diff.
3143
3144 The current directory when running this command shall be the top
3145 level directory of the U-Boot source tree, or it's parent directory
3146 (i. e. please make sure that your patch includes sufficient
3147 directory information for the affected files).
3148
3149 We accept patches as plain text, MIME attachments or as uuencoded
3150 gzipped text.
3151
3152 * If one logical set of modifications affects or creates several
3153 files, all these changes shall be submitted in a SINGLE patch file.
3154
3155 * Changesets that contain different, unrelated modifications shall be
3156 submitted as SEPARATE patches, one patch per changeset.
3157
3158
3159 Notes:
3160
3161 * Before sending the patch, run the MAKEALL script on your patched
3162 source tree and make sure that no errors or warnings are reported
3163 for any of the boards.
3164
3165 * Keep your modifications to the necessary minimum: A patch
3166 containing several unrelated changes or arbitrary reformats will be
3167 returned with a request to re-formatting / split it.
3168
3169 * If you modify existing code, make sure that your new code does not
3170 add to the memory footprint of the code ;-) Small is beautiful!
3171 When adding new features, these should compile conditionally only
3172 (using #ifdef), and the resulting code with the new feature
3173 disabled must not need more memory than the old code without your
3174 modification.