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wdenkc6097192002-11-03 00:24:07 +00001#
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
24Summary:
25========
26
wdenk24ee89b2002-11-03 17:56:27 +000027This directory contains the source code for U-Boot, a boot loader for
28Embedded boards based on PowerPC and ARM processors, which can be
29installed in a boot ROM and used to initialize and test the hardware
30or to download and run application code.
wdenkc6097192002-11-03 00:24:07 +000031
32The development of U-Boot is closely related to Linux: some parts of
wdenk24ee89b2002-11-03 17:56:27 +000033the source code originate in the Linux source tree, we have some
34header files in common, and special provision has been made to
wdenkc6097192002-11-03 00:24:07 +000035support booting of Linux images.
36
37Some attention has been paid to make this software easily
38configurable and extendable. For instance, all monitor commands are
39implemented with the same call interface, so that it's very easy to
40add new commands. Also, instead of permanently adding rarely used
41code (for instance hardware test utilities) to the monitor, you can
42load and run it dynamically.
43
44
45Status:
46=======
47
48In general, all boards for which a configuration option exists in the
wdenk24ee89b2002-11-03 17:56:27 +000049Makefile have been tested to some extent and can be considered
wdenkc6097192002-11-03 00:24:07 +000050"working". In fact, many of them are used in production systems.
51
wdenk24ee89b2002-11-03 17:56:27 +000052In case of problems see the CHANGELOG and CREDITS files to find out
wdenkc6097192002-11-03 00:24:07 +000053who contributed the specific port.
54
wdenkc6097192002-11-03 00:24:07 +000055
56Where to get help:
57==================
58
wdenk24ee89b2002-11-03 17:56:27 +000059In case you have questions about, problems with or contributions for
60U-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
62previous traffic on the mailing list - please search the archive
wdenkc6097192002-11-03 00:24:07 +000063before asking FAQ's. Please see
64http://lists.sourceforge.net/lists/listinfo/u-boot-users/
65
66
67Where we come from:
68===================
69
70- start from 8xxrom sources
wdenk24ee89b2002-11-03 17:56:27 +000071- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
wdenkc6097192002-11-03 00:24:07 +000072- 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
wdenk24ee89b2002-11-03 17:56:27 +000080- create ARMBoot project (http://sourceforge.net/projects/armboot)
wdenkc6097192002-11-03 00:24:07 +000081- add other CPU families (starting with ARM)
wdenk24ee89b2002-11-03 17:56:27 +000082- create U-Boot project (http://sourceforge.net/projects/u-boot)
83
84
85Names and Spelling:
86===================
87
88The "official" name of this project is "Das U-Boot". The spelling
89"U-Boot" shall be used in all written text (documentation, comments
90in source files etc.). Example:
91
92 This is the README file for the U-Boot project.
93
94File 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
100Variable names, preprocessor constants etc. shall be either based on
101the 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
wdenkc6097192002-11-03 00:24:07 +0000105
106
wdenk93f19cc2002-12-17 17:55:09 +0000107Versioning:
108===========
109
110U-Boot uses a 3 level version number containing a version, a
111sub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
112sub-version "34", and patchlevel "4".
113
114The patchlevel is used to indicate certain stages of development
115between released versions, i. e. officially released versions of
116U-Boot will always have a patchlevel of "0".
117
118
wdenkc6097192002-11-03 00:24:07 +0000119Directory Hierarchy:
120====================
121
122- board Board dependend files
123- common Misc architecture independend functions
124- cpu CPU specific files
125- disk Code for disk drive partition handling
126- doc Documentation (don't expect too much)
127- drivers Common 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
wdenk0db5bca2003-03-31 17:27:09 +0000143- cpu/mpc5xx Files specific to Motorola MPC5xx CPUs
wdenkc6097192002-11-03 00:24:07 +0000144- cpu/mpc8xx Files specific to Motorola MPC8xx CPUs
145- cpu/mpc824x Files specific to Motorola MPC824x CPUs
146- cpu/mpc8260 Files specific to Motorola MPC8260 CPU
147- cpu/ppc4xx Files specific to IBM 4xx CPUs
148
wdenk3bac3512003-03-12 10:41:04 +0000149- board/LEOX/ Files specific to boards manufactured by The LEOX team
150- board/LEOX/elpt860 Files specific to ELPT860 boards
wdenkc6097192002-11-03 00:24:07 +0000151- board/RPXClassic
152 Files specific to RPXClassic boards
153- board/RPXlite Files specific to RPXlite boards
154- board/c2mon Files specific to c2mon boards
wdenk0db5bca2003-03-31 17:27:09 +0000155- board/cmi Files specific to cmi boards
wdenkc6097192002-11-03 00:24:07 +0000156- board/cogent Files specific to Cogent boards
157 (need further configuration)
158 Files specific to CPCIISER4 boards
159- board/cpu86 Files specific to CPU86 boards
160- board/cray/ Files specific to boards manufactured by Cray
161- board/cray/L1 Files specific to L1 boards
162- board/cu824 Files specific to CU824 boards
163- board/ebony Files specific to IBM Ebony board
164- board/eric Files specific to ERIC boards
165- board/esd/ Files specific to boards manufactured by ESD
166- board/esd/adciop Files specific to ADCIOP boards
167- board/esd/ar405 Files specific to AR405 boards
168- board/esd/canbt Files specific to CANBT boards
169- board/esd/cpci405 Files specific to CPCI405 boards
170- board/esd/cpciiser4 Files specific to CPCIISER4 boards
171- board/esd/common Common files for ESD boards
172- board/esd/dasa_sim Files specific to DASA_SIM boards
173- board/esd/du405 Files specific to DU405 boards
174- board/esd/ocrtc Files specific to OCRTC boards
175- board/esd/pci405 Files specific to PCI405 boards
176- board/esteem192e
177 Files specific to ESTEEM192E boards
178- board/etx094 Files specific to ETX_094 boards
179- board/evb64260
180 Files specific to EVB64260 boards
181- board/fads Files specific to FADS boards
182- board/flagadm Files specific to FLAGADM boards
wdenk7aa78612003-05-03 15:50:43 +0000183- board/gen860t Files specific to GEN860T and GEN860T_SC boards
wdenkc6097192002-11-03 00:24:07 +0000184- board/genietv Files specific to GENIETV boards
185- board/gth Files specific to GTH boards
186- board/hermes Files specific to HERMES boards
187- board/hymod Files specific to HYMOD boards
188- board/icu862 Files specific to ICU862 boards
189- board/ip860 Files specific to IP860 boards
190- board/iphase4539
191 Files specific to Interphase4539 boards
192- board/ivm Files specific to IVMS8/IVML24 boards
193- board/lantec Files specific to LANTEC boards
194- board/lwmon Files specific to LWMON boards
195- board/mbx8xx Files specific to MBX boards
196- board/mpc8260ads
197 Files specific to MMPC8260ADS boards
198- board/mpl/ Files specific to boards manufactured by MPL
199- board/mpl/common Common files for MPL boards
200- board/mpl/pip405 Files specific to PIP405 boards
201- board/mpl/mip405 Files specific to MIP405 boards
202- board/musenki Files specific to MUSEKNI boards
203- board/mvs1 Files specific to MVS1 boards
204- board/nx823 Files specific to NX823 boards
205- board/oxc Files specific to OXC boards
206- board/pcippc2 Files specific to PCIPPC2/PCIPPC6 boards
207- board/pm826 Files specific to PM826 boards
208- board/ppmc8260
209 Files specific to PPMC8260 boards
210- board/rpxsuper
211 Files specific to RPXsuper boards
212- board/rsdproto
213 Files specific to RSDproto boards
214- board/sandpoint
215 Files specific to Sandpoint boards
216- board/sbc8260 Files specific to SBC8260 boards
217- board/sacsng Files specific to SACSng boards
218- board/siemens Files specific to boards manufactured by Siemens AG
219- board/siemens/CCM Files specific to CCM boards
220- board/siemens/IAD210 Files specific to IAD210 boards
221- board/siemens/SCM Files specific to SCM boards
222- board/siemens/pcu_e Files specific to PCU_E boards
223- board/sixnet Files specific to SIXNET boards
224- board/spd8xx Files specific to SPD8xxTS boards
225- board/tqm8260 Files specific to TQM8260 boards
226- board/tqm8xx Files specific to TQM8xxL boards
227- board/w7o Files specific to W7O boards
228- board/walnut405
229 Files specific to Walnut405 boards
230- board/westel/ Files specific to boards manufactured by Westel Wireless
231- board/westel/amx860 Files specific to AMX860 boards
232- board/utx8245 Files specific to UTX8245 boards
233
234Software Configuration:
235=======================
236
237Configuration is usually done using C preprocessor defines; the
238rationale behind that is to avoid dead code whenever possible.
239
240There are two classes of configuration variables:
241
242* Configuration _OPTIONS_:
243 These are selectable by the user and have names beginning with
244 "CONFIG_".
245
246* Configuration _SETTINGS_:
247 These depend on the hardware etc. and should not be meddled with if
248 you don't know what you're doing; they have names beginning with
249 "CFG_".
250
251Later we will add a configuration tool - probably similar to or even
252identical to what's used for the Linux kernel. Right now, we have to
253do the configuration by hand, which means creating some symbolic
254links and editing some configuration files. We use the TQM8xxL boards
255as an example here.
256
257
258Selection of Processor Architecture and Board Type:
259---------------------------------------------------
260
261For all supported boards there are ready-to-use default
262configurations available; just type "make <board_name>_config".
263
264Example: For a TQM823L module type:
265
266 cd u-boot
267 make TQM823L_config
268
269For the Cogent platform, you need to specify the cpu type as well;
270e.g. "make cogent_mpc8xx_config". And also configure the cogent
271directory according to the instructions in cogent/README.
272
273
274Configuration Options:
275----------------------
276
277Configuration depends on the combination of board and CPU type; all
278such information is kept in a configuration file
279"include/configs/<board_name>.h".
280
281Example: For a TQM823L module, all configuration settings are in
282"include/configs/TQM823L.h".
283
284
wdenk7f6c2cb2002-11-10 22:06:23 +0000285Many of the options are named exactly as the corresponding Linux
286kernel configuration options. The intention is to make it easier to
287build a config tool - later.
288
289
wdenkc6097192002-11-03 00:24:07 +0000290The following options need to be configured:
291
292- CPU Type: Define exactly one of
293
294 PowerPC based CPUs:
295 -------------------
296 CONFIG_MPC823, CONFIG_MPC850, CONFIG_MPC855, CONFIG_MPC860
wdenk0db5bca2003-03-31 17:27:09 +0000297 or CONFIG_MPC5xx
wdenkc6097192002-11-03 00:24:07 +0000298 or CONFIG_MPC824X, CONFIG_MPC8260
299 or CONFIG_IOP480
300 or CONFIG_405GP
301 or CONFIG_440
302 or CONFIG_MPC74xx
303
304 ARM based CPUs:
305 ---------------
306 CONFIG_SA1110
307 CONFIG_ARM7
308 CONFIG_PXA250
309
310
311- Board Type: Define exactly one of
312
313 PowerPC based boards:
314 ---------------------
315
316 CONFIG_ADCIOP, CONFIG_ICU862 CONFIG_RPXsuper,
317 CONFIG_ADS860, CONFIG_IP860, CONFIG_SM850,
318 CONFIG_AMX860, CONFIG_IPHASE4539, CONFIG_SPD823TS,
319 CONFIG_AR405, CONFIG_IVML24, CONFIG_SXNI855T,
320 CONFIG_BAB7xx, CONFIG_IVML24_128, CONFIG_Sandpoint8240,
321 CONFIG_CANBT, CONFIG_IVML24_256, CONFIG_Sandpoint8245,
322 CONFIG_CCM, CONFIG_IVMS8, CONFIG_TQM823L,
323 CONFIG_CPCI405, CONFIG_IVMS8_128, CONFIG_TQM850L,
324 CONFIG_CPCI4052, CONFIG_IVMS8_256, CONFIG_TQM855L,
325 CONFIG_CPCIISER4, CONFIG_LANTEC, CONFIG_TQM860L,
326 CONFIG_CPU86, CONFIG_MBX, CONFIG_TQM8260,
327 CONFIG_CRAYL1, CONFIG_MBX860T, CONFIG_TTTech,
328 CONFIG_CU824, CONFIG_MHPC, CONFIG_UTX8245,
329 CONFIG_DASA_SIM, CONFIG_MIP405, CONFIG_W7OLMC,
330 CONFIG_DU405, CONFIG_MOUSSE, CONFIG_W7OLMG,
331 CONFIG_ELPPC, CONFIG_MPC8260ADS, CONFIG_WALNUT405,
332 CONFIG_ERIC, CONFIG_MUSENKI, CONFIG_ZUMA,
333 CONFIG_ESTEEM192E, CONFIG_MVS1, CONFIG_c2mon,
334 CONFIG_ETX094, CONFIG_NX823, CONFIG_cogent_mpc8260,
335 CONFIG_EVB64260, CONFIG_OCRTC, CONFIG_cogent_mpc8xx,
336 CONFIG_FADS823, CONFIG_ORSG, CONFIG_ep8260,
337 CONFIG_FADS850SAR, CONFIG_OXC, CONFIG_gw8260,
338 CONFIG_FADS860T, CONFIG_PCI405, CONFIG_hermes,
339 CONFIG_FLAGADM, CONFIG_PCIPPC2, CONFIG_hymod,
340 CONFIG_FPS850L, CONFIG_PCIPPC6, CONFIG_lwmon,
341 CONFIG_GEN860T, CONFIG_PIP405, CONFIG_pcu_e,
342 CONFIG_GENIETV, CONFIG_PM826, CONFIG_ppmc8260,
343 CONFIG_GTH, CONFIG_RPXClassic, CONFIG_rsdproto,
344 CONFIG_IAD210, CONFIG_RPXlite, CONFIG_sbc8260,
wdenk608c9142003-01-13 23:54:46 +0000345 CONFIG_EBONY, CONFIG_sacsng, CONFIG_FPS860L,
wdenk0db5bca2003-03-31 17:27:09 +0000346 CONFIG_V37, CONFIG_ELPT860, CONFIG_CMI
wdenkc6097192002-11-03 00:24:07 +0000347
348 ARM based boards:
349 -----------------
350
351 CONFIG_HHP_CRADLE, CONFIG_DNP1110, CONFIG_EP7312,
352 CONFIG_IMPA7, CONFIG_LART, CONFIG_LUBBOCK,
353 CONFIG_SHANNON, CONFIG_SMDK2400, CONFIG_SMDK2410,
354 CONFIG_TRAB
355
356
357- CPU Module Type: (if CONFIG_COGENT is defined)
358 Define exactly one of
359 CONFIG_CMA286_60_OLD
360--- FIXME --- not tested yet:
361 CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
362 CONFIG_CMA287_23, CONFIG_CMA287_50
363
364- Motherboard Type: (if CONFIG_COGENT is defined)
365 Define exactly one of
366 CONFIG_CMA101, CONFIG_CMA102
367
368- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
369 Define one or more of
370 CONFIG_CMA302
371
372- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
373 Define one or more of
374 CONFIG_LCD_HEARTBEAT - update a character position on
375 the lcd display every second with
376 a "rotator" |\-/|\-/
377
378- MPC824X Family Member (if CONFIG_MPC824X is defined)
379 Define exactly one of
380 CONFIG_MPC8240, CONFIG_MPC8245
381
382- 8xx CPU Options: (if using an 8xx cpu)
383 Define one or more of
384 CONFIG_8xx_GCLK_FREQ - if get_gclk_freq() can not work e.g.
385 no 32KHz reference PIT/RTC clock
386
387- Clock Interface:
388 CONFIG_CLOCKS_IN_MHZ
389
390 U-Boot stores all clock information in Hz
391 internally. For binary compatibility with older Linux
392 kernels (which expect the clocks passed in the
393 bd_info data to be in MHz) the environment variable
394 "clocks_in_mhz" can be defined so that U-Boot
395 converts clock data to MHZ before passing it to the
396 Linux kernel.
397
398 When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
399 "clocks_in_mhz=1" is automatically included in the
400 default environment.
401
402- Console Interface:
wdenk43d96162003-03-06 00:02:04 +0000403 Depending on board, define exactly one serial port
404 (like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
405 CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
406 console by defining CONFIG_8xx_CONS_NONE
wdenkc6097192002-11-03 00:24:07 +0000407
408 Note: if CONFIG_8xx_CONS_NONE is defined, the serial
409 port routines must be defined elsewhere
410 (i.e. serial_init(), serial_getc(), ...)
411
412 CONFIG_CFB_CONSOLE
413 Enables console device for a color framebuffer. Needs following
414 defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
415 VIDEO_FB_LITTLE_ENDIAN graphic memory organisation
416 (default big endian)
417 VIDEO_HW_RECTFILL graphic chip supports
418 rectangle fill
419 (cf. smiLynxEM)
420 VIDEO_HW_BITBLT graphic chip supports
421 bit-blit (cf. smiLynxEM)
422 VIDEO_VISIBLE_COLS visible pixel columns
423 (cols=pitch)
424 VIDEO_VISIBLE_ROWS visible pixel rows
425 VIDEO_PIXEL_SIZE bytes per pixel
426 VIDEO_DATA_FORMAT graphic data format
427 (0-5, cf. cfb_console.c)
428 VIDEO_FB_ADRS framebuffer address
429 VIDEO_KBD_INIT_FCT keyboard int fct
430 (i.e. i8042_kbd_init())
431 VIDEO_TSTC_FCT test char fct
432 (i.e. i8042_tstc)
433 VIDEO_GETC_FCT get char fct
434 (i.e. i8042_getc)
435 CONFIG_CONSOLE_CURSOR cursor drawing on/off
436 (requires blink timer
437 cf. i8042.c)
438 CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
439 CONFIG_CONSOLE_TIME display time/date info in
440 upper right corner
441 (requires CFG_CMD_DATE)
442 CONFIG_VIDEO_LOGO display Linux logo in
443 upper left corner
wdenka6c7ad22002-12-03 21:28:10 +0000444 CONFIG_VIDEO_BMP_LOGO use bmp_logo.h instead of
445 linux_logo.h for logo.
446 Requires CONFIG_VIDEO_LOGO
wdenkc6097192002-11-03 00:24:07 +0000447 CONFIG_CONSOLE_EXTRA_INFO
448 addional board info beside
449 the logo
450
wdenk43d96162003-03-06 00:02:04 +0000451 When CONFIG_CFB_CONSOLE is defined, video console is
452 default i/o. Serial console can be forced with
453 environment 'console=serial'.
wdenkc6097192002-11-03 00:24:07 +0000454
455- Console Baudrate:
456 CONFIG_BAUDRATE - in bps
457 Select one of the baudrates listed in
458 CFG_BAUDRATE_TABLE, see below.
459
460- Interrupt driven serial port input:
461 CONFIG_SERIAL_SOFTWARE_FIFO
462
463 PPC405GP only.
464 Use an interrupt handler for receiving data on the
465 serial port. It also enables using hardware handshake
466 (RTS/CTS) and UART's built-in FIFO. Set the number of
467 bytes the interrupt driven input buffer should have.
468
469 Set to 0 to disable this feature (this is the default).
470 This will also disable hardware handshake.
471
472- Boot Delay: CONFIG_BOOTDELAY - in seconds
473 Delay before automatically booting the default image;
474 set to -1 to disable autoboot.
475
476 See doc/README.autoboot for these options that
477 work with CONFIG_BOOTDELAY. None are required.
478 CONFIG_BOOT_RETRY_TIME
479 CONFIG_BOOT_RETRY_MIN
480 CONFIG_AUTOBOOT_KEYED
481 CONFIG_AUTOBOOT_PROMPT
482 CONFIG_AUTOBOOT_DELAY_STR
483 CONFIG_AUTOBOOT_STOP_STR
484 CONFIG_AUTOBOOT_DELAY_STR2
485 CONFIG_AUTOBOOT_STOP_STR2
486 CONFIG_ZERO_BOOTDELAY_CHECK
487 CONFIG_RESET_TO_RETRY
488
489- Autoboot Command:
490 CONFIG_BOOTCOMMAND
491 Only needed when CONFIG_BOOTDELAY is enabled;
492 define a command string that is automatically executed
493 when no character is read on the console interface
494 within "Boot Delay" after reset.
495
496 CONFIG_BOOTARGS
wdenk43d96162003-03-06 00:02:04 +0000497 This can be used to pass arguments to the bootm
498 command. The value of CONFIG_BOOTARGS goes into the
499 environment value "bootargs".
wdenkc6097192002-11-03 00:24:07 +0000500
501 CONFIG_RAMBOOT and CONFIG_NFSBOOT
wdenk43d96162003-03-06 00:02:04 +0000502 The value of these goes into the environment as
503 "ramboot" and "nfsboot" respectively, and can be used
504 as a convenience, when switching between booting from
505 ram and nfs.
wdenkc6097192002-11-03 00:24:07 +0000506
507- Pre-Boot Commands:
508 CONFIG_PREBOOT
509
510 When this option is #defined, the existence of the
511 environment variable "preboot" will be checked
512 immediately before starting the CONFIG_BOOTDELAY
513 countdown and/or running the auto-boot command resp.
514 entering interactive mode.
515
516 This feature is especially useful when "preboot" is
517 automatically generated or modified. For an example
518 see the LWMON board specific code: here "preboot" is
519 modified when the user holds down a certain
520 combination of keys on the (special) keyboard when
521 booting the systems
522
523- Serial Download Echo Mode:
524 CONFIG_LOADS_ECHO
525 If defined to 1, all characters received during a
526 serial download (using the "loads" command) are
527 echoed back. This might be needed by some terminal
528 emulations (like "cu"), but may as well just take
529 time on others. This setting #define's the initial
530 value of the "loads_echo" environment variable.
531
532- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
533 CONFIG_KGDB_BAUDRATE
534 Select one of the baudrates listed in
535 CFG_BAUDRATE_TABLE, see below.
536
537- Monitor Functions:
538 CONFIG_COMMANDS
539 Most monitor functions can be selected (or
540 de-selected) by adjusting the definition of
541 CONFIG_COMMANDS; to select individual functions,
542 #define CONFIG_COMMANDS by "OR"ing any of the
543 following values:
544
545 #define enables commands:
546 -------------------------
547 CFG_CMD_ASKENV * ask for env variable
548 CFG_CMD_BDI bdinfo
549 CFG_CMD_BEDBUG Include BedBug Debugger
550 CFG_CMD_BOOTD bootd
551 CFG_CMD_CACHE icache, dcache
552 CFG_CMD_CONSOLE coninfo
553 CFG_CMD_DATE * support for RTC, date/time...
554 CFG_CMD_DHCP DHCP support
555 CFG_CMD_ECHO * echo arguments
556 CFG_CMD_EEPROM * EEPROM read/write support
557 CFG_CMD_ELF bootelf, bootvx
558 CFG_CMD_ENV saveenv
559 CFG_CMD_FDC * Floppy Disk Support
wdenk2262cfe2002-11-18 00:14:45 +0000560 CFG_CMD_FDOS * Dos diskette Support
wdenkc6097192002-11-03 00:24:07 +0000561 CFG_CMD_FLASH flinfo, erase, protect
562 CFG_CMD_FPGA FPGA device initialization support
563 CFG_CMD_I2C * I2C serial bus support
564 CFG_CMD_IDE * IDE harddisk support
565 CFG_CMD_IMI iminfo
566 CFG_CMD_IMMAP * IMMR dump support
567 CFG_CMD_IRQ * irqinfo
568 CFG_CMD_KGDB * kgdb
569 CFG_CMD_LOADB loadb
570 CFG_CMD_LOADS loads
571 CFG_CMD_MEMORY md, mm, nm, mw, cp, cmp, crc, base,
572 loop, mtest
573 CFG_CMD_MII MII utility commands
574 CFG_CMD_NET bootp, tftpboot, rarpboot
575 CFG_CMD_PCI * pciinfo
576 CFG_CMD_PCMCIA * PCMCIA support
577 CFG_CMD_REGINFO * Register dump
578 CFG_CMD_RUN run command in env variable
579 CFG_CMD_SCSI * SCSI Support
580 CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
581 CFG_CMD_SPI * SPI serial bus support
582 CFG_CMD_USB * USB support
583 CFG_CMD_BSP * Board SPecific functions
584 -----------------------------------------------
585 CFG_CMD_ALL all
586
587 CFG_CMD_DFL Default configuration; at the moment
588 this is includes all commands, except
589 the ones marked with "*" in the list
590 above.
591
592 If you don't define CONFIG_COMMANDS it defaults to
593 CFG_CMD_DFL in include/cmd_confdefs.h. A board can
594 override the default settings in the respective
595 include file.
596
597 EXAMPLE: If you want all functions except of network
598 support you can write:
599
600 #define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
601
602
603 Note: Don't enable the "icache" and "dcache" commands
wdenk43d96162003-03-06 00:02:04 +0000604 (configuration option CFG_CMD_CACHE) unless you know
605 what you (and your U-Boot users) are doing. Data
606 cache cannot be enabled on systems like the 8xx or
607 8260 (where accesses to the IMMR region must be
608 uncached), and it cannot be disabled on all other
609 systems where we (mis-) use the data cache to hold an
610 initial stack and some data.
wdenkc6097192002-11-03 00:24:07 +0000611
612
613 XXX - this list needs to get updated!
614
615- Watchdog:
616 CONFIG_WATCHDOG
617 If this variable is defined, it enables watchdog
618 support. There must support in the platform specific
619 code for a watchdog. For the 8xx and 8260 CPUs, the
620 SIU Watchdog feature is enabled in the SYPCR
621 register.
622
stroesec1551ea2003-04-04 15:53:41 +0000623- U-Boot Version:
624 CONFIG_VERSION_VARIABLE
625 If this variable is defined, an environment variable
626 named "ver" is created by U-Boot showing the U-Boot
627 version as printed by the "version" command.
628 This variable is readonly.
629
wdenkc6097192002-11-03 00:24:07 +0000630- Real-Time Clock:
631
632 When CFG_CMD_DATE is selected, the type of the RTC
633 has to be selected, too. Define exactly one of the
634 following options:
635
636 CONFIG_RTC_MPC8xx - use internal RTC of MPC8xx
637 CONFIG_RTC_PCF8563 - use Philips PCF8563 RTC
638 CONFIG_RTC_MC146818 - use MC146818 RTC
wdenk1cb8e982003-03-06 21:55:29 +0000639 CONFIG_RTC_DS1307 - use Maxim, Inc. DS1307 RTC
wdenkc6097192002-11-03 00:24:07 +0000640 CONFIG_RTC_DS1337 - use Maxim, Inc. DS1337 RTC
wdenk3bac3512003-03-12 10:41:04 +0000641 CONFIG_RTC_DS164x - use Dallas DS164x RTC
wdenkc6097192002-11-03 00:24:07 +0000642
643- Timestamp Support:
644
wdenk43d96162003-03-06 00:02:04 +0000645 When CONFIG_TIMESTAMP is selected, the timestamp
646 (date and time) of an image is printed by image
647 commands like bootm or iminfo. This option is
648 automatically enabled when you select CFG_CMD_DATE .
wdenkc6097192002-11-03 00:24:07 +0000649
650- Partition Support:
651 CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
652 and/or CONFIG_ISO_PARTITION
653
654 If IDE or SCSI support is enabled (CFG_CMD_IDE or
655 CFG_CMD_SCSI) you must configure support for at least
656 one partition type as well.
657
658- IDE Reset method:
659 CONFIG_IDE_RESET_ROUTINE
660
661 Set this to define that instead of a reset Pin, the
662 routine ide_set_reset(int idereset) will be used.
663
664- ATAPI Support:
665 CONFIG_ATAPI
666
667 Set this to enable ATAPI support.
668
669- SCSI Support:
670 At the moment only there is only support for the
671 SYM53C8XX SCSI controller; define
672 CONFIG_SCSI_SYM53C8XX to enable it.
673
674 CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
675 CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
676 CFG_SCSI_MAX_LUN] can be adjusted to define the
677 maximum numbers of LUNs, SCSI ID's and target
678 devices.
679 CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
680
681- NETWORK Support (PCI):
682 CONFIG_EEPRO100
683 Support for Intel 82557/82559/82559ER chips.
684 Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
685 write routine for first time initialisation.
686
687 CONFIG_TULIP
688 Support for Digital 2114x chips.
689 Optional CONFIG_TULIP_SELECT_MEDIA for board specific
690 modem chip initialisation (KS8761/QS6611).
691
692 CONFIG_NATSEMI
693 Support for National dp83815 chips.
694
695 CONFIG_NS8382X
696 Support for National dp8382[01] gigabit chips.
697
wdenk45219c42003-05-12 21:50:16 +0000698- NETWORK Support (other):
699
700 CONFIG_DRIVER_LAN91C96
701 Support for SMSC's LAN91C96 chips.
702
703 CONFIG_LAN91C96_BASE
704 Define this to hold the physical address
705 of the LAN91C96's I/O space
706
707 CONFIG_LAN91C96_USE_32_BIT
708 Define this to enable 32 bit addressing
709
wdenkc6097192002-11-03 00:24:07 +0000710- USB Support:
711 At the moment only the UHCI host controller is
712 supported (PIP405, MIP405); define
713 CONFIG_USB_UHCI to enable it.
714 define CONFIG_USB_KEYBOARD to enable the USB Keyboard
715 end define CONFIG_USB_STORAGE to enable the USB
716 storage devices.
717 Note:
718 Supported are USB Keyboards and USB Floppy drives
719 (TEAC FD-05PUB).
720
721- Keyboard Support:
722 CONFIG_ISA_KEYBOARD
723
724 Define this to enable standard (PC-Style) keyboard
725 support
726
727 CONFIG_I8042_KBD
728 Standard PC keyboard driver with US (is default) and
729 GERMAN key layout (switch via environment 'keymap=de') support.
730 Export function i8042_kbd_init, i8042_tstc and i8042_getc
731 for cfb_console. Supports cursor blinking.
732
733- Video support:
734 CONFIG_VIDEO
735
736 Define this to enable video support (for output to
737 video).
738
739 CONFIG_VIDEO_CT69000
740
741 Enable Chips & Technologies 69000 Video chip
742
743 CONFIG_VIDEO_SMI_LYNXEM
744 Enable Silicon Motion SMI 712/710/810 Video chip
745 Videomode are selected via environment 'videomode' with
746 standard LiLo mode numbers.
747 Following modes are supported (* is default):
748
wdenk43d96162003-03-06 00:02:04 +0000749 800x600 1024x768 1280x1024
750 256 (8bit) 303* 305 307
751 65536 (16bit) 314 317 31a
752 16,7 Mill (24bit) 315 318 31b
wdenkc6097192002-11-03 00:24:07 +0000753 (i.e. setenv videomode 317; saveenv; reset;)
754
stroesec1551ea2003-04-04 15:53:41 +0000755 CONFIG_VIDEO_SED13806
wdenk43d96162003-03-06 00:02:04 +0000756 Enable Epson SED13806 driver. This driver supports 8bpp
wdenka6c7ad22002-12-03 21:28:10 +0000757 and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
758 or CONFIG_VIDEO_SED13806_16BPP
759
760
wdenkc6097192002-11-03 00:24:07 +0000761- LCD Support: CONFIG_LCD
762
763 Define this to enable LCD support (for output to LCD
764 display); also select one of the supported displays
765 by defining one of these:
766
767 CONFIG_NEC_NL6648AC33:
768
769 NEC NL6648AC33-18. Active, color, single scan.
770
771 CONFIG_NEC_NL6648BC20
772
773 NEC NL6648BC20-08. 6.5", 640x480.
774 Active, color, single scan.
775
776 CONFIG_SHARP_16x9
777
778 Sharp 320x240. Active, color, single scan.
779 It isn't 16x9, and I am not sure what it is.
780
781 CONFIG_SHARP_LQ64D341
782
783 Sharp LQ64D341 display, 640x480.
784 Active, color, single scan.
785
786 CONFIG_HLD1045
787
788 HLD1045 display, 640x480.
789 Active, color, single scan.
790
791 CONFIG_OPTREX_BW
792
793 Optrex CBL50840-2 NF-FW 99 22 M5
794 or
795 Hitachi LMG6912RPFC-00T
796 or
797 Hitachi SP14Q002
798
799 320x240. Black & white.
800
801 Normally display is black on white background; define
802 CFG_WHITE_ON_BLACK to get it inverted.
803
wdenkd791b1d2003-04-20 14:04:18 +0000804- Spash Screen Support: CONFIG_SPLASH_SCREEN
805
806 If this option is set, the environment is checked for
807 a variable "splashimage". If found, the usual display
808 of logo, copyright and system information on the LCD
809 is supressed and the BMP image at the address
810 specified in "splashimage" is loaded instead. The
811 console is redirected to the "nulldev", too. This
812 allows for a "silent" boot where a splash screen is
813 loaded very quickly after power-on.
814
815
wdenkc6097192002-11-03 00:24:07 +0000816- Ethernet address:
817 CONFIG_ETHADDR
818 CONFIG_ETH2ADDR
819 CONFIG_ETH3ADDR
820
821 Define a default value for ethernet address to use
822 for the respective ethernet interface, in case this
823 is not determined automatically.
824
825- IP address:
826 CONFIG_IPADDR
827
828 Define a default value for the IP address to use for
829 the default ethernet interface, in case this is not
830 determined through e.g. bootp.
831
832- Server IP address:
833 CONFIG_SERVERIP
834
835 Defines a default value for theIP address of a TFTP
836 server to contact when using the "tftboot" command.
837
838- BOOTP Recovery Mode:
839 CONFIG_BOOTP_RANDOM_DELAY
840
841 If you have many targets in a network that try to
842 boot using BOOTP, you may want to avoid that all
843 systems send out BOOTP requests at precisely the same
844 moment (which would happen for instance at recovery
845 from a power failure, when all systems will try to
846 boot, thus flooding the BOOTP server. Defining
847 CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
848 inserted before sending out BOOTP requests. The
849 following delays are insterted then:
850
851 1st BOOTP request: delay 0 ... 1 sec
852 2nd BOOTP request: delay 0 ... 2 sec
853 3rd BOOTP request: delay 0 ... 4 sec
854 4th and following
855 BOOTP requests: delay 0 ... 8 sec
856
857- Status LED: CONFIG_STATUS_LED
858
859 Several configurations allow to display the current
860 status using a LED. For instance, the LED will blink
861 fast while running U-Boot code, stop blinking as
862 soon as a reply to a BOOTP request was received, and
863 start blinking slow once the Linux kernel is running
864 (supported by a status LED driver in the Linux
865 kernel). Defining CONFIG_STATUS_LED enables this
866 feature in U-Boot.
867
868- CAN Support: CONFIG_CAN_DRIVER
869
870 Defining CONFIG_CAN_DRIVER enables CAN driver support
871 on those systems that support this (optional)
872 feature, like the TQM8xxL modules.
873
874- I2C Support: CONFIG_HARD_I2C | CONFIG_SOFT_I2C
875
876 Enables I2C serial bus commands. If this is selected,
877 either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
878 to include the appropriate I2C driver.
879
wdenk43d96162003-03-06 00:02:04 +0000880 See also: common/cmd_i2c.c for a description of the
881 command line interface.
wdenkc6097192002-11-03 00:24:07 +0000882
883
884 CONFIG_HARD_I2C
885
886 Selects the CPM hardware driver for I2C.
887
888 CONFIG_SOFT_I2C
889
890 Use software (aka bit-banging) driver instead of CPM
891 or similar hardware support for I2C. This is configured
892 via the following defines.
893
894 I2C_INIT
895
wdenk43d96162003-03-06 00:02:04 +0000896 (Optional). Any commands necessary to enable I2C
897 controller or configure ports.
wdenkc6097192002-11-03 00:24:07 +0000898
899 I2C_PORT
900
wdenk43d96162003-03-06 00:02:04 +0000901 (Only for MPC8260 CPU). The I/O port to use (the code
902 assumes both bits are on the same port). Valid values
903 are 0..3 for ports A..D.
wdenkc6097192002-11-03 00:24:07 +0000904
905 I2C_ACTIVE
906
907 The code necessary to make the I2C data line active
908 (driven). If the data line is open collector, this
909 define can be null.
910
911 I2C_TRISTATE
912
913 The code necessary to make the I2C data line tri-stated
914 (inactive). If the data line is open collector, this
915 define can be null.
916
917 I2C_READ
918
919 Code that returns TRUE if the I2C data line is high,
920 FALSE if it is low.
921
922 I2C_SDA(bit)
923
924 If <bit> is TRUE, sets the I2C data line high. If it
925 is FALSE, it clears it (low).
926
927 I2C_SCL(bit)
928
929 If <bit> is TRUE, sets the I2C clock line high. If it
930 is FALSE, it clears it (low).
931
932 I2C_DELAY
933
934 This delay is invoked four times per clock cycle so this
935 controls the rate of data transfer. The data rate thus
936 is 1 / (I2C_DELAY * 4).
937
wdenk47cd00f2003-03-06 13:39:27 +0000938 CFG_I2C_INIT_BOARD
939
940 When a board is reset during an i2c bus transfer
941 chips might think that the current transfer is still
942 in progress. On some boards it is possible to access
943 the i2c SCLK line directly, either by using the
944 processor pin as a GPIO or by having a second pin
945 connected to the bus. If this option is defined a
946 custom i2c_init_board() routine in boards/xxx/board.c
947 is run early in the boot sequence.
948
wdenkc6097192002-11-03 00:24:07 +0000949- SPI Support: CONFIG_SPI
950
951 Enables SPI driver (so far only tested with
952 SPI EEPROM, also an instance works with Crystal A/D and
953 D/As on the SACSng board)
954
955 CONFIG_SPI_X
956
957 Enables extended (16-bit) SPI EEPROM addressing.
958 (symmetrical to CONFIG_I2C_X)
959
960 CONFIG_SOFT_SPI
961
wdenk43d96162003-03-06 00:02:04 +0000962 Enables a software (bit-bang) SPI driver rather than
963 using hardware support. This is a general purpose
964 driver that only requires three general I/O port pins
965 (two outputs, one input) to function. If this is
966 defined, the board configuration must define several
967 SPI configuration items (port pins to use, etc). For
968 an example, see include/configs/sacsng.h.
wdenkc6097192002-11-03 00:24:07 +0000969
970- FPGA Support: CONFIG_FPGA_COUNT
971
wdenk43d96162003-03-06 00:02:04 +0000972 Specify the number of FPGA devices to support.
wdenkc6097192002-11-03 00:24:07 +0000973
wdenk43d96162003-03-06 00:02:04 +0000974 CONFIG_FPGA
wdenkc6097192002-11-03 00:24:07 +0000975
wdenk43d96162003-03-06 00:02:04 +0000976 Used to specify the types of FPGA devices. For
wdenkc6097192002-11-03 00:24:07 +0000977 example,
978 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
979
980 CFG_FPGA_PROG_FEEDBACK
981
wdenk43d96162003-03-06 00:02:04 +0000982 Enable printing of hash marks during FPGA
wdenkc6097192002-11-03 00:24:07 +0000983 configuration.
984
985 CFG_FPGA_CHECK_BUSY
986
wdenk43d96162003-03-06 00:02:04 +0000987 Enable checks on FPGA configuration interface busy
988 status by the configuration function. This option
989 will require a board or device specific function to
990 be written.
wdenkc6097192002-11-03 00:24:07 +0000991
992 CONFIG_FPGA_DELAY
993
wdenk43d96162003-03-06 00:02:04 +0000994 If defined, a function that provides delays in the
995 FPGA configuration driver.
wdenkc6097192002-11-03 00:24:07 +0000996
997 CFG_FPGA_CHECK_CTRLC
998
999 Allow Control-C to interrupt FPGA configuration
1000
1001 CFG_FPGA_CHECK_ERROR
1002
wdenk43d96162003-03-06 00:02:04 +00001003 Check for configuration errors during FPGA bitfile
1004 loading. For example, abort during Virtex II
1005 configuration if the INIT_B line goes low (which
1006 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001007
1008 CFG_FPGA_WAIT_INIT
1009
wdenk43d96162003-03-06 00:02:04 +00001010 Maximum time to wait for the INIT_B line to deassert
1011 after PROB_B has been deasserted during a Virtex II
1012 FPGA configuration sequence. The default time is 500 mS.
wdenkc6097192002-11-03 00:24:07 +00001013
1014 CFG_FPGA_WAIT_BUSY
1015
wdenk43d96162003-03-06 00:02:04 +00001016 Maximum time to wait for BUSY to deassert during
1017 Virtex II FPGA configuration. The default is 5 mS.
wdenkc6097192002-11-03 00:24:07 +00001018
1019 CFG_FPGA_WAIT_CONFIG
1020
wdenk43d96162003-03-06 00:02:04 +00001021 Time to wait after FPGA configuration. The default is
wdenkc6097192002-11-03 00:24:07 +00001022 200 mS.
1023
1024- FPGA Support: CONFIG_FPGA_COUNT
1025
1026 Specify the number of FPGA devices to support.
1027
1028 CONFIG_FPGA
1029
1030 Used to specify the types of FPGA devices. For example,
1031 #define CONFIG_FPGA CFG_XILINX_VIRTEX2
1032
1033 CFG_FPGA_PROG_FEEDBACK
1034
1035 Enable printing of hash marks during FPGA configuration.
1036
1037 CFG_FPGA_CHECK_BUSY
1038
wdenk43d96162003-03-06 00:02:04 +00001039 Enable checks on FPGA configuration interface busy
1040 status by the configuration function. This option
1041 will require a board or device specific function to
1042 be written.
wdenkc6097192002-11-03 00:24:07 +00001043
1044 CONFIG_FPGA_DELAY
1045
1046 If defined, a function that provides delays in the FPGA
1047 configuration driver.
1048
1049 CFG_FPGA_CHECK_CTRLC
1050 Allow Control-C to interrupt FPGA configuration
1051
1052 CFG_FPGA_CHECK_ERROR
1053
wdenk43d96162003-03-06 00:02:04 +00001054 Check for configuration errors during FPGA bitfile
1055 loading. For example, abort during Virtex II
1056 configuration if the INIT_B line goes low (which
1057 indicated a CRC error).
wdenkc6097192002-11-03 00:24:07 +00001058
1059 CFG_FPGA_WAIT_INIT
1060
wdenk43d96162003-03-06 00:02:04 +00001061 Maximum time to wait for the INIT_B line to deassert
1062 after PROB_B has been deasserted during a Virtex II
1063 FPGA configuration sequence. The default time is 500
1064 mS.
wdenkc6097192002-11-03 00:24:07 +00001065
1066 CFG_FPGA_WAIT_BUSY
1067
wdenk43d96162003-03-06 00:02:04 +00001068 Maximum time to wait for BUSY to deassert during
1069 Virtex II FPGA configuration. The default is 5 mS.
wdenkc6097192002-11-03 00:24:07 +00001070
1071 CFG_FPGA_WAIT_CONFIG
1072
wdenk43d96162003-03-06 00:02:04 +00001073 Time to wait after FPGA configuration. The default is
1074 200 mS.
wdenkc6097192002-11-03 00:24:07 +00001075
1076- Configuration Management:
1077 CONFIG_IDENT_STRING
1078
wdenk43d96162003-03-06 00:02:04 +00001079 If defined, this string will be added to the U-Boot
1080 version information (U_BOOT_VERSION)
wdenkc6097192002-11-03 00:24:07 +00001081
1082- Vendor Parameter Protection:
1083
wdenk43d96162003-03-06 00:02:04 +00001084 U-Boot considers the values of the environment
1085 variables "serial#" (Board Serial Number) and
1086 "ethaddr" (Ethernet Address) to bb parameters that
1087 are set once by the board vendor / manufacturer, and
1088 protects these variables from casual modification by
1089 the user. Once set, these variables are read-only,
1090 and write or delete attempts are rejected. You can
1091 change this behviour:
wdenkc6097192002-11-03 00:24:07 +00001092
1093 If CONFIG_ENV_OVERWRITE is #defined in your config
1094 file, the write protection for vendor parameters is
wdenk47cd00f2003-03-06 13:39:27 +00001095 completely disabled. Anybody can change or delete
wdenkc6097192002-11-03 00:24:07 +00001096 these parameters.
1097
1098 Alternatively, if you #define _both_ CONFIG_ETHADDR
1099 _and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1100 ethernet address is installed in the environment,
1101 which can be changed exactly ONCE by the user. [The
1102 serial# is unaffected by this, i. e. it remains
1103 read-only.]
1104
1105- Protected RAM:
1106 CONFIG_PRAM
1107
1108 Define this variable to enable the reservation of
1109 "protected RAM", i. e. RAM which is not overwritten
1110 by U-Boot. Define CONFIG_PRAM to hold the number of
1111 kB you want to reserve for pRAM. You can overwrite
1112 this default value by defining an environment
1113 variable "pram" to the number of kB you want to
1114 reserve. Note that the board info structure will
1115 still show the full amount of RAM. If pRAM is
1116 reserved, a new environment variable "mem" will
1117 automatically be defined to hold the amount of
1118 remaining RAM in a form that can be passed as boot
1119 argument to Linux, for instance like that:
1120
1121 setenv bootargs ... mem=\$(mem)
1122 saveenv
1123
1124 This way you can tell Linux not to use this memory,
1125 either, which results in a memory region that will
1126 not be affected by reboots.
1127
1128 *WARNING* If your board configuration uses automatic
1129 detection of the RAM size, you must make sure that
1130 this memory test is non-destructive. So far, the
1131 following board configurations are known to be
1132 "pRAM-clean":
1133
1134 ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1135 HERMES, IP860, RPXlite, LWMON, LANTEC,
1136 PCU_E, FLAGADM, TQM8260
1137
1138- Error Recovery:
1139 CONFIG_PANIC_HANG
1140
1141 Define this variable to stop the system in case of a
1142 fatal error, so that you have to reset it manually.
1143 This is probably NOT a good idea for an embedded
1144 system where you want to system to reboot
1145 automatically as fast as possible, but it may be
1146 useful during development since you can try to debug
1147 the conditions that lead to the situation.
1148
1149 CONFIG_NET_RETRY_COUNT
1150
wdenk43d96162003-03-06 00:02:04 +00001151 This variable defines the number of retries for
1152 network operations like ARP, RARP, TFTP, or BOOTP
1153 before giving up the operation. If not defined, a
1154 default value of 5 is used.
wdenkc6097192002-11-03 00:24:07 +00001155
1156- Command Interpreter:
1157 CFG_HUSH_PARSER
1158
1159 Define this variable to enable the "hush" shell (from
1160 Busybox) as command line interpreter, thus enabling
1161 powerful command line syntax like
1162 if...then...else...fi conditionals or `&&' and '||'
1163 constructs ("shell scripts").
1164
1165 If undefined, you get the old, much simpler behaviour
1166 with a somewhat smaller memory footprint.
1167
1168
1169 CFG_PROMPT_HUSH_PS2
1170
1171 This defines the secondary prompt string, which is
1172 printed when the command interpreter needs more input
1173 to complete a command. Usually "> ".
1174
1175 Note:
1176
wdenk43d96162003-03-06 00:02:04 +00001177 In the current implementation, the local variables
1178 space and global environment variables space are
1179 separated. Local variables are those you define by
1180 simply typing like `name=value'. To access a local
1181 variable later on, you have write `$name' or
1182 `${name}'; variable directly by typing say `$name' at
1183 the command prompt.
wdenkc6097192002-11-03 00:24:07 +00001184
wdenk43d96162003-03-06 00:02:04 +00001185 Global environment variables are those you use
1186 setenv/printenv to work with. To run a command stored
1187 in such a variable, you need to use the run command,
1188 and you must not use the '$' sign to access them.
wdenkc6097192002-11-03 00:24:07 +00001189
1190 To store commands and special characters in a
1191 variable, please use double quotation marks
1192 surrounding the whole text of the variable, instead
1193 of the backslashes before semicolons and special
1194 symbols.
1195
1196- Default Environment
1197 CONFIG_EXTRA_ENV_SETTINGS
1198
wdenk43d96162003-03-06 00:02:04 +00001199 Define this to contain any number of null terminated
1200 strings (variable = value pairs) that will be part of
1201 the default enviroment compiled into the boot image.
wdenk2262cfe2002-11-18 00:14:45 +00001202
wdenk43d96162003-03-06 00:02:04 +00001203 For example, place something like this in your
1204 board's config file:
wdenkc6097192002-11-03 00:24:07 +00001205
1206 #define CONFIG_EXTRA_ENV_SETTINGS \
1207 "myvar1=value1\0" \
1208 "myvar2=value2\0"
1209
wdenk43d96162003-03-06 00:02:04 +00001210 Warning: This method is based on knowledge about the
1211 internal format how the environment is stored by the
1212 U-Boot code. This is NOT an official, exported
1213 interface! Although it is unlikely that this format
1214 will change soon, but there is no guarantee either.
wdenkc6097192002-11-03 00:24:07 +00001215 You better know what you are doing here.
1216
wdenk43d96162003-03-06 00:02:04 +00001217 Note: overly (ab)use of the default environment is
1218 discouraged. Make sure to check other ways to preset
1219 the environment like the autoscript function or the
1220 boot command first.
wdenkc6097192002-11-03 00:24:07 +00001221
1222- Show boot progress
1223 CONFIG_SHOW_BOOT_PROGRESS
1224
wdenk43d96162003-03-06 00:02:04 +00001225 Defining this option allows to add some board-
1226 specific code (calling a user-provided function
1227 "show_boot_progress(int)") that enables you to show
1228 the system's boot progress on some display (for
1229 example, some LED's) on your board. At the moment,
1230 the following checkpoints are implemented:
wdenkc6097192002-11-03 00:24:07 +00001231
1232 Arg Where When
1233 1 common/cmd_bootm.c before attempting to boot an image
1234 -1 common/cmd_bootm.c Image header has bad magic number
1235 2 common/cmd_bootm.c Image header has correct magic number
1236 -2 common/cmd_bootm.c Image header has bad checksum
1237 3 common/cmd_bootm.c Image header has correct checksum
1238 -3 common/cmd_bootm.c Image data has bad checksum
1239 4 common/cmd_bootm.c Image data has correct checksum
1240 -4 common/cmd_bootm.c Image is for unsupported architecture
1241 5 common/cmd_bootm.c Architecture check OK
1242 -5 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1243 6 common/cmd_bootm.c Image Type check OK
1244 -6 common/cmd_bootm.c gunzip uncompression error
1245 -7 common/cmd_bootm.c Unimplemented compression type
1246 7 common/cmd_bootm.c Uncompression OK
1247 -8 common/cmd_bootm.c Wrong Image Type (not kernel, multi, standalone)
1248 8 common/cmd_bootm.c Image Type check OK
1249 -9 common/cmd_bootm.c Unsupported OS (not Linux, BSD, VxWorks, QNX)
1250 9 common/cmd_bootm.c Start initial ramdisk verification
1251 -10 common/cmd_bootm.c Ramdisk header has bad magic number
1252 -11 common/cmd_bootm.c Ramdisk header has bad checksum
1253 10 common/cmd_bootm.c Ramdisk header is OK
1254 -12 common/cmd_bootm.c Ramdisk data has bad checksum
1255 11 common/cmd_bootm.c Ramdisk data has correct checksum
1256 12 common/cmd_bootm.c Ramdisk verification complete, start loading
1257 -13 common/cmd_bootm.c Wrong Image Type (not PPC Linux Ramdisk)
1258 13 common/cmd_bootm.c Start multifile image verification
1259 14 common/cmd_bootm.c No initial ramdisk, no multifile, continue.
1260 15 common/cmd_bootm.c All preparation done, transferring control to OS
1261
1262 -1 common/cmd_doc.c Bad usage of "doc" command
1263 -1 common/cmd_doc.c No boot device
1264 -1 common/cmd_doc.c Unknown Chip ID on boot device
1265 -1 common/cmd_doc.c Read Error on boot device
1266 -1 common/cmd_doc.c Image header has bad magic number
1267
1268 -1 common/cmd_ide.c Bad usage of "ide" command
1269 -1 common/cmd_ide.c No boot device
1270 -1 common/cmd_ide.c Unknown boot device
1271 -1 common/cmd_ide.c Unknown partition table
1272 -1 common/cmd_ide.c Invalid partition type
1273 -1 common/cmd_ide.c Read Error on boot device
1274 -1 common/cmd_ide.c Image header has bad magic number
1275
1276 -1 common/cmd_nvedit.c Environment not changable, but has bad CRC
1277
1278
1279Modem Support:
1280--------------
1281
wdenk85ec0bc2003-03-31 16:34:49 +00001282[so far only for SMDK2400 and TRAB boards]
wdenkc6097192002-11-03 00:24:07 +00001283
1284- Modem support endable:
1285 CONFIG_MODEM_SUPPORT
1286
1287- RTS/CTS Flow control enable:
1288 CONFIG_HWFLOW
1289
1290- Modem debug support:
1291 CONFIG_MODEM_SUPPORT_DEBUG
1292
wdenk43d96162003-03-06 00:02:04 +00001293 Enables debugging stuff (char screen[1024], dbg())
1294 for modem support. Useful only with BDI2000.
wdenkc6097192002-11-03 00:24:07 +00001295
1296- General:
1297
wdenk43d96162003-03-06 00:02:04 +00001298 In the target system modem support is enabled when a
1299 specific key (key combination) is pressed during
1300 power-on. Otherwise U-Boot will boot normally
1301 (autoboot). The key_pressed() fuction is called from
1302 board_init(). Currently key_pressed() is a dummy
1303 function, returning 1 and thus enabling modem
1304 initialization.
wdenkc6097192002-11-03 00:24:07 +00001305
wdenk43d96162003-03-06 00:02:04 +00001306 If there are no modem init strings in the
1307 environment, U-Boot proceed to autoboot; the
1308 previous output (banner, info printfs) will be
1309 supressed, though.
wdenkc6097192002-11-03 00:24:07 +00001310
1311 See also: doc/README.Modem
1312
1313
1314
1315
1316Configuration Settings:
1317-----------------------
1318
1319- CFG_LONGHELP: Defined when you want long help messages included;
1320 undefine this when you're short of memory.
1321
1322- CFG_PROMPT: This is what U-Boot prints on the console to
1323 prompt for user input.
1324
1325- CFG_CBSIZE: Buffer size for input from the Console
1326
1327- CFG_PBSIZE: Buffer size for Console output
1328
1329- CFG_MAXARGS: max. Number of arguments accepted for monitor commands
1330
1331- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1332 the application (usually a Linux kernel) when it is
1333 booted
1334
1335- CFG_BAUDRATE_TABLE:
1336 List of legal baudrate settings for this board.
1337
1338- CFG_CONSOLE_INFO_QUIET
1339 Suppress display of console information at boot.
1340
1341- CFG_CONSOLE_IS_IN_ENV
1342 If the board specific function
1343 extern int overwrite_console (void);
1344 returns 1, the stdin, stderr and stdout are switched to the
1345 serial port, else the settings in the environment are used.
1346
1347- CFG_CONSOLE_OVERWRITE_ROUTINE
1348 Enable the call to overwrite_console().
1349
1350- CFG_CONSOLE_ENV_OVERWRITE
1351 Enable overwrite of previous console environment settings.
1352
1353- CFG_MEMTEST_START, CFG_MEMTEST_END:
1354 Begin and End addresses of the area used by the
1355 simple memory test.
1356
1357- CFG_ALT_MEMTEST:
1358 Enable an alternate, more extensive memory test.
1359
1360- CFG_TFTP_LOADADDR:
1361 Default load address for network file downloads
1362
1363- CFG_LOADS_BAUD_CHANGE:
1364 Enable temporary baudrate change while serial download
1365
1366- CFG_SDRAM_BASE:
1367 Physical start address of SDRAM. _Must_ be 0 here.
1368
1369- CFG_MBIO_BASE:
1370 Physical start address of Motherboard I/O (if using a
1371 Cogent motherboard)
1372
1373- CFG_FLASH_BASE:
1374 Physical start address of Flash memory.
1375
1376- CFG_MONITOR_BASE:
1377 Physical start address of boot monitor code (set by
1378 make config files to be same as the text base address
1379 (TEXT_BASE) used when linking) - same as
1380 CFG_FLASH_BASE when booting from flash.
1381
1382- CFG_MONITOR_LEN:
1383 Size of memory reserved for monitor code
1384
1385- CFG_MALLOC_LEN:
1386 Size of DRAM reserved for malloc() use.
1387
1388- CFG_BOOTMAPSZ:
1389 Maximum size of memory mapped by the startup code of
1390 the Linux kernel; all data that must be processed by
1391 the Linux kernel (bd_info, boot arguments, eventually
1392 initrd image) must be put below this limit.
1393
1394- CFG_MAX_FLASH_BANKS:
1395 Max number of Flash memory banks
1396
1397- CFG_MAX_FLASH_SECT:
1398 Max number of sectors on a Flash chip
1399
1400- CFG_FLASH_ERASE_TOUT:
1401 Timeout for Flash erase operations (in ms)
1402
1403- CFG_FLASH_WRITE_TOUT:
1404 Timeout for Flash write operations (in ms)
1405
1406- CFG_DIRECT_FLASH_TFTP:
1407
1408 Enable TFTP transfers directly to flash memory;
1409 without this option such a download has to be
1410 performed in two steps: (1) download to RAM, and (2)
1411 copy from RAM to flash.
1412
1413 The two-step approach is usually more reliable, since
1414 you can check if the download worked before you erase
1415 the flash, but in some situations (when sytem RAM is
1416 too limited to allow for a tempory copy of the
1417 downloaded image) this option may be very useful.
1418
1419- CFG_FLASH_CFI:
wdenk43d96162003-03-06 00:02:04 +00001420 Define if the flash driver uses extra elements in the
1421 common flash structure for storing flash geometry
wdenkc6097192002-11-03 00:24:07 +00001422
1423The following definitions that deal with the placement and management
1424of environment data (variable area); in general, we support the
1425following configurations:
1426
1427- CFG_ENV_IS_IN_FLASH:
1428
1429 Define this if the environment is in flash memory.
1430
1431 a) The environment occupies one whole flash sector, which is
1432 "embedded" in the text segment with the U-Boot code. This
1433 happens usually with "bottom boot sector" or "top boot
1434 sector" type flash chips, which have several smaller
1435 sectors at the start or the end. For instance, such a
1436 layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1437 such a case you would place the environment in one of the
1438 4 kB sectors - with U-Boot code before and after it. With
1439 "top boot sector" type flash chips, you would put the
1440 environment in one of the last sectors, leaving a gap
1441 between U-Boot and the environment.
1442
1443 - CFG_ENV_OFFSET:
1444
1445 Offset of environment data (variable area) to the
1446 beginning of flash memory; for instance, with bottom boot
1447 type flash chips the second sector can be used: the offset
1448 for this sector is given here.
1449
1450 CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1451
1452 - CFG_ENV_ADDR:
1453
1454 This is just another way to specify the start address of
1455 the flash sector containing the environment (instead of
1456 CFG_ENV_OFFSET).
1457
1458 - CFG_ENV_SECT_SIZE:
1459
1460 Size of the sector containing the environment.
1461
1462
1463 b) Sometimes flash chips have few, equal sized, BIG sectors.
1464 In such a case you don't want to spend a whole sector for
1465 the environment.
1466
1467 - CFG_ENV_SIZE:
1468
1469 If you use this in combination with CFG_ENV_IS_IN_FLASH
1470 and CFG_ENV_SECT_SIZE, you can specify to use only a part
1471 of this flash sector for the environment. This saves
1472 memory for the RAM copy of the environment.
1473
1474 It may also save flash memory if you decide to use this
1475 when your environment is "embedded" within U-Boot code,
1476 since then the remainder of the flash sector could be used
1477 for U-Boot code. It should be pointed out that this is
1478 STRONGLY DISCOURAGED from a robustness point of view:
1479 updating the environment in flash makes it always
1480 necessary to erase the WHOLE sector. If something goes
1481 wrong before the contents has been restored from a copy in
1482 RAM, your target system will be dead.
1483
1484 - CFG_ENV_ADDR_REDUND
1485 CFG_ENV_SIZE_REDUND
1486
wdenk43d96162003-03-06 00:02:04 +00001487 These settings describe a second storage area used to hold
1488 a redundand copy of the environment data, so that there is
wdenk3e386912003-04-05 00:53:31 +00001489 a valid backup copy in case there is a power failure during
wdenk43d96162003-03-06 00:02:04 +00001490 a "saveenv" operation.
wdenkc6097192002-11-03 00:24:07 +00001491
1492BE CAREFUL! Any changes to the flash layout, and some changes to the
1493source code will make it necessary to adapt <board>/u-boot.lds*
1494accordingly!
1495
1496
1497- CFG_ENV_IS_IN_NVRAM:
1498
1499 Define this if you have some non-volatile memory device
1500 (NVRAM, battery buffered SRAM) which you want to use for the
1501 environment.
1502
1503 - CFG_ENV_ADDR:
1504 - CFG_ENV_SIZE:
1505
1506 These two #defines are used to determin the memory area you
1507 want to use for environment. It is assumed that this memory
1508 can just be read and written to, without any special
1509 provision.
1510
1511BE CAREFUL! The first access to the environment happens quite early
1512in U-Boot initalization (when we try to get the setting of for the
1513console baudrate). You *MUST* have mappend your NVRAM area then, or
1514U-Boot will hang.
1515
1516Please note that even with NVRAM we still use a copy of the
1517environment in RAM: we could work on NVRAM directly, but we want to
1518keep settings there always unmodified except somebody uses "saveenv"
1519to save the current settings.
1520
1521
1522- CFG_ENV_IS_IN_EEPROM:
1523
1524 Use this if you have an EEPROM or similar serial access
1525 device and a driver for it.
1526
1527 - CFG_ENV_OFFSET:
1528 - CFG_ENV_SIZE:
1529
1530 These two #defines specify the offset and size of the
1531 environment area within the total memory of your EEPROM.
1532
1533 - CFG_I2C_EEPROM_ADDR:
1534 If defined, specified the chip address of the EEPROM device.
1535 The default address is zero.
1536
1537 - CFG_EEPROM_PAGE_WRITE_BITS:
1538 If defined, the number of bits used to address bytes in a
1539 single page in the EEPROM device. A 64 byte page, for example
1540 would require six bits.
1541
1542 - CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1543 If defined, the number of milliseconds to delay between
1544 page writes. The default is zero milliseconds.
1545
1546 - CFG_I2C_EEPROM_ADDR_LEN:
1547 The length in bytes of the EEPROM memory array address. Note
1548 that this is NOT the chip address length!
1549
1550 - CFG_EEPROM_SIZE:
1551 The size in bytes of the EEPROM device.
1552
wdenkc6097192002-11-03 00:24:07 +00001553
1554- CFG_SPI_INIT_OFFSET
1555
1556 Defines offset to the initial SPI buffer area in DPRAM. The
1557 area is used at an early stage (ROM part) if the environment
1558 is configured to reside in the SPI EEPROM: We need a 520 byte
1559 scratch DPRAM area. It is used between the two initialization
1560 calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1561 to be a good choice since it makes it far enough from the
1562 start of the data area as well as from the stack pointer.
1563
1564Please note that the environment is read-only as long as the monitor
1565has been relocated to RAM and a RAM copy of the environment has been
1566created; also, when using EEPROM you will have to use getenv_r()
1567until then to read environment variables.
1568
wdenk85ec0bc2003-03-31 16:34:49 +00001569The environment is protected by a CRC32 checksum. Before the monitor
1570is relocated into RAM, as a result of a bad CRC you will be working
1571with the compiled-in default environment - *silently*!!! [This is
1572necessary, because the first environment variable we need is the
1573"baudrate" setting for the console - if we have a bad CRC, we don't
1574have any device yet where we could complain.]
wdenkc6097192002-11-03 00:24:07 +00001575
1576Note: once the monitor has been relocated, then it will complain if
1577the default environment is used; a new CRC is computed as soon as you
wdenk85ec0bc2003-03-31 16:34:49 +00001578use the "saveenv" command to store a valid environment.
wdenkc6097192002-11-03 00:24:07 +00001579
1580
wdenkc6097192002-11-03 00:24:07 +00001581Low Level (hardware related) configuration options:
wdenkdc7c9a12003-03-26 06:55:25 +00001582---------------------------------------------------
wdenkc6097192002-11-03 00:24:07 +00001583
1584- CFG_CACHELINE_SIZE:
1585 Cache Line Size of the CPU.
1586
1587- CFG_DEFAULT_IMMR:
1588 Default address of the IMMR after system reset.
1589 Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1590 to be able to adjust the position of the IMMR
1591 register after a reset.
1592
wdenk7f6c2cb2002-11-10 22:06:23 +00001593- Floppy Disk Support:
1594 CFG_FDC_DRIVE_NUMBER
1595
1596 the default drive number (default value 0)
1597
1598 CFG_ISA_IO_STRIDE
1599
1600 defines the spacing between fdc chipset registers
1601 (default value 1)
1602
1603 CFG_ISA_IO_OFFSET
1604
wdenk43d96162003-03-06 00:02:04 +00001605 defines the offset of register from address. It
1606 depends on which part of the data bus is connected to
1607 the fdc chipset. (default value 0)
wdenk7f6c2cb2002-11-10 22:06:23 +00001608
wdenk43d96162003-03-06 00:02:04 +00001609 If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1610 CFG_FDC_DRIVE_NUMBER are undefined, they take their
1611 default value.
wdenk7f6c2cb2002-11-10 22:06:23 +00001612
wdenk43d96162003-03-06 00:02:04 +00001613 if CFG_FDC_HW_INIT is defined, then the function
1614 fdc_hw_init() is called at the beginning of the FDC
1615 setup. fdc_hw_init() must be provided by the board
1616 source code. It is used to make hardware dependant
1617 initializations.
wdenk7f6c2cb2002-11-10 22:06:23 +00001618
wdenkc6097192002-11-03 00:24:07 +00001619- CFG_IMMR: Physical address of the Internal Memory Mapped
1620 Register; DO NOT CHANGE! (11-4)
1621 [MPC8xx systems only]
1622
1623- CFG_INIT_RAM_ADDR:
1624
1625 Start address of memory area tha can be used for
1626 initial data and stack; please note that this must be
1627 writable memory that is working WITHOUT special
1628 initialization, i. e. you CANNOT use normal RAM which
1629 will become available only after programming the
1630 memory controller and running certain initialization
1631 sequences.
1632
1633 U-Boot uses the following memory types:
1634 - MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1635 - MPC824X: data cache
1636 - PPC4xx: data cache
1637
wdenk85ec0bc2003-03-31 16:34:49 +00001638- CFG_GBL_DATA_OFFSET:
wdenkc6097192002-11-03 00:24:07 +00001639
1640 Offset of the initial data structure in the memory
1641 area defined by CFG_INIT_RAM_ADDR. Usually
wdenk85ec0bc2003-03-31 16:34:49 +00001642 CFG_GBL_DATA_OFFSET is chosen such that the initial
wdenkc6097192002-11-03 00:24:07 +00001643 data is located at the end of the available space
1644 (sometimes written as (CFG_INIT_RAM_END -
1645 CFG_INIT_DATA_SIZE), and the initial stack is just
1646 below that area (growing from (CFG_INIT_RAM_ADDR +
wdenk85ec0bc2003-03-31 16:34:49 +00001647 CFG_GBL_DATA_OFFSET) downward.
wdenkc6097192002-11-03 00:24:07 +00001648
1649 Note:
1650 On the MPC824X (or other systems that use the data
1651 cache for initial memory) the address chosen for
1652 CFG_INIT_RAM_ADDR is basically arbitrary - it must
1653 point to an otherwise UNUSED address space between
1654 the top of RAM and the start of the PCI space.
1655
1656- CFG_SIUMCR: SIU Module Configuration (11-6)
1657
1658- CFG_SYPCR: System Protection Control (11-9)
1659
1660- CFG_TBSCR: Time Base Status and Control (11-26)
1661
1662- CFG_PISCR: Periodic Interrupt Status and Control (11-31)
1663
1664- CFG_PLPRCR: PLL, Low-Power, and Reset Control Register (15-30)
1665
1666- CFG_SCCR: System Clock and reset Control Register (15-27)
1667
1668- CFG_OR_TIMING_SDRAM:
1669 SDRAM timing
1670
1671- CFG_MAMR_PTA:
1672 periodic timer for refresh
1673
1674- CFG_DER: Debug Event Register (37-47)
1675
1676- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1677 CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1678 CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1679 CFG_BR1_PRELIM:
1680 Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1681
1682- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1683 CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1684 CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1685 Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1686
1687- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1688 CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1689 Machine Mode Register and Memory Periodic Timer
1690 Prescaler definitions (SDRAM timing)
1691
1692- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1693 enable I2C microcode relocation patch (MPC8xx);
1694 define relocation offset in DPRAM [DSP2]
1695
1696- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1697 enable SPI microcode relocation patch (MPC8xx);
1698 define relocation offset in DPRAM [SCC4]
1699
1700- CFG_USE_OSCCLK:
1701 Use OSCM clock mode on MBX8xx board. Be careful,
1702 wrong setting might damage your board. Read
1703 doc/README.MBX before setting this variable!
1704
wdenkea909b72002-11-21 23:11:29 +00001705- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
wdenk43d96162003-03-06 00:02:04 +00001706 Offset of the bootmode word in DPRAM used by post
1707 (Power On Self Tests). This definition overrides
1708 #define'd default value in commproc.h resp.
1709 cpm_8260.h.
wdenkea909b72002-11-21 23:11:29 +00001710
wdenkc6097192002-11-03 00:24:07 +00001711Building the Software:
1712======================
1713
1714Building U-Boot has been tested in native PPC environments (on a
1715PowerBook G3 running LinuxPPC 2000) and in cross environments
1716(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1717NetBSD 1.5 on x86).
1718
1719If you are not using a native PPC environment, it is assumed that you
1720have the GNU cross compiling tools available in your path and named
1721with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1722you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1723the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1724change it to:
1725
1726 CROSS_COMPILE = ppc_4xx-
1727
1728
1729U-Boot is intended to be simple to build. After installing the
1730sources you must configure U-Boot for one specific board type. This
1731is done by typing:
1732
1733 make NAME_config
1734
1735where "NAME_config" is the name of one of the existing
1736configurations; the following names are supported:
1737
1738 ADCIOP_config GTH_config TQM850L_config
1739 ADS860_config IP860_config TQM855L_config
1740 AR405_config IVML24_config TQM860L_config
1741 CANBT_config IVMS8_config WALNUT405_config
1742 CPCI405_config LANTEC_config cogent_common_config
1743 CPCIISER4_config MBX_config cogent_mpc8260_config
1744 CU824_config MBX860T_config cogent_mpc8xx_config
1745 ESTEEM192E_config RPXlite_config hermes_config
1746 ETX094_config RPXsuper_config hymod_config
1747 FADS823_config SM850_config lwmon_config
1748 FADS850SAR_config SPD823TS_config pcu_e_config
1749 FADS860T_config SXNI855T_config rsdproto_config
1750 FPS850L_config Sandpoint8240_config sbc8260_config
1751 GENIETV_config TQM823L_config PIP405_config
wdenk384ae022002-11-05 00:17:55 +00001752 GEN860T_config EBONY_config FPS860L_config
wdenk0db5bca2003-03-31 17:27:09 +00001753 ELPT860_config cmi_mpc5xx_config
wdenkc6097192002-11-03 00:24:07 +00001754
1755Note: for some board special configuration names may exist; check if
1756 additional information is available from the board vendor; for
1757 instance, the TQM8xxL systems run normally at 50 MHz and use a
1758 SCC for 10baseT ethernet; there are also systems with 80 MHz
1759 CPU clock, and an optional Fast Ethernet module is available
1760 for CPU's with FEC. You can select such additional "features"
1761 when chosing the configuration, i. e.
1762
1763 make TQM860L_config
1764 - will configure for a plain TQM860L, i. e. 50MHz, no FEC
1765
1766 make TQM860L_FEC_config
1767 - will configure for a TQM860L at 50MHz with FEC for ethernet
1768
1769 make TQM860L_80MHz_config
1770 - will configure for a TQM860L at 80 MHz, with normal 10baseT
1771 interface
1772
1773 make TQM860L_FEC_80MHz_config
1774 - will configure for a TQM860L at 80 MHz with FEC for ethernet
1775
1776 make TQM823L_LCD_config
1777 - will configure for a TQM823L with U-Boot console on LCD
1778
1779 make TQM823L_LCD_80MHz_config
1780 - will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1781
1782 etc.
1783
1784
1785
wdenk24ee89b2002-11-03 17:56:27 +00001786Finally, type "make all", and you should get some working U-Boot
wdenkc6097192002-11-03 00:24:07 +00001787images ready for downlod to / installation on your system:
1788
1789- "u-boot.bin" is a raw binary image
1790- "u-boot" is an image in ELF binary format
1791- "u-boot.srec" is in Motorola S-Record format
1792
1793
1794Please be aware that the Makefiles assume you are using GNU make, so
1795for instance on NetBSD you might need to use "gmake" instead of
1796native "make".
1797
1798
1799If the system board that you have is not listed, then you will need
1800to port U-Boot to your hardware platform. To do this, follow these
1801steps:
1802
18031. Add a new configuration option for your board to the toplevel
wdenk85ec0bc2003-03-31 16:34:49 +00001804 "Makefile" and to the "MAKEALL" script, using the existing
1805 entries as examples. Note that here and at many other places
1806 boards and other names are listed alphabetically sorted. Please
1807 keep this order.
wdenkc6097192002-11-03 00:24:07 +000018082. Create a new directory to hold your board specific code. Add any
wdenk85ec0bc2003-03-31 16:34:49 +00001809 files you need. In your board directory, you will need at least
1810 the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
18113. Create a new configuration file "include/configs/<board>.h" for
1812 your board
wdenkc6097192002-11-03 00:24:07 +000018133. If you're porting U-Boot to a new CPU, then also create a new
1814 directory to hold your CPU specific code. Add any files you need.
wdenk85ec0bc2003-03-31 16:34:49 +000018154. Run "make <board>_config" with your new name.
wdenkc6097192002-11-03 00:24:07 +000018165. Type "make", and you should get a working "u-boot.srec" file
1817 to be installed on your target system.
wdenk85ec0bc2003-03-31 16:34:49 +000018186. Debug and solve any problems that might arise.
wdenkc6097192002-11-03 00:24:07 +00001819 [Of course, this last step is much harder than it sounds.]
1820
1821
1822Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1823==============================================================
1824
1825If you have modified U-Boot sources (for instance added a new board
1826or support for new devices, a new CPU, etc.) you are expected to
1827provide feedback to the other developers. The feedback normally takes
1828the form of a "patch", i. e. a context diff against a certain (latest
1829official or latest in CVS) version of U-Boot sources.
1830
1831But before you submit such a patch, please verify that your modifi-
1832cation did not break existing code. At least make sure that *ALL* of
1833the supported boards compile WITHOUT ANY compiler warnings. To do so,
1834just run the "MAKEALL" script, which will configure and build U-Boot
1835for ALL supported system. Be warned, this will take a while. You can
1836select which (cross) compiler to use py passing a `CROSS_COMPILE'
1837environment variable to the script, i. e. to use the cross tools from
1838MontaVista's Hard Hat Linux you can type
1839
1840 CROSS_COMPILE=ppc_8xx- MAKEALL
1841
1842or to build on a native PowerPC system you can type
1843
1844 CROSS_COMPILE=' ' MAKEALL
1845
1846See also "U-Boot Porting Guide" below.
1847
1848
1849
1850Monitor Commands - Overview:
1851============================
1852
1853go - start application at address 'addr'
1854run - run commands in an environment variable
1855bootm - boot application image from memory
1856bootp - boot image via network using BootP/TFTP protocol
1857tftpboot- boot image via network using TFTP protocol
1858 and env variables "ipaddr" and "serverip"
1859 (and eventually "gatewayip")
1860rarpboot- boot image via network using RARP/TFTP protocol
1861diskboot- boot from IDE devicebootd - boot default, i.e., run 'bootcmd'
1862loads - load S-Record file over serial line
1863loadb - load binary file over serial line (kermit mode)
1864md - memory display
1865mm - memory modify (auto-incrementing)
1866nm - memory modify (constant address)
1867mw - memory write (fill)
1868cp - memory copy
1869cmp - memory compare
1870crc32 - checksum calculation
1871imd - i2c memory display
1872imm - i2c memory modify (auto-incrementing)
1873inm - i2c memory modify (constant address)
1874imw - i2c memory write (fill)
1875icrc32 - i2c checksum calculation
1876iprobe - probe to discover valid I2C chip addresses
1877iloop - infinite loop on address range
1878isdram - print SDRAM configuration information
1879sspi - SPI utility commands
1880base - print or set address offset
1881printenv- print environment variables
1882setenv - set environment variables
1883saveenv - save environment variables to persistent storage
1884protect - enable or disable FLASH write protection
1885erase - erase FLASH memory
1886flinfo - print FLASH memory information
1887bdinfo - print Board Info structure
1888iminfo - print header information for application image
1889coninfo - print console devices and informations
1890ide - IDE sub-system
1891loop - infinite loop on address range
1892mtest - simple RAM test
1893icache - enable or disable instruction cache
1894dcache - enable or disable data cache
1895reset - Perform RESET of the CPU
1896echo - echo args to console
1897version - print monitor version
1898help - print online help
1899? - alias for 'help'
1900
1901
1902Monitor Commands - Detailed Description:
1903========================================
1904
1905TODO.
1906
1907For now: just type "help <command>".
1908
1909
1910Environment Variables:
1911======================
1912
1913U-Boot supports user configuration using Environment Variables which
1914can be made persistent by saving to Flash memory.
1915
1916Environment Variables are set using "setenv", printed using
1917"printenv", and saved to Flash using "saveenv". Using "setenv"
1918without a value can be used to delete a variable from the
1919environment. As long as you don't save the environment you are
1920working with an in-memory copy. In case the Flash area containing the
1921environment is erased by accident, a default environment is provided.
1922
1923Some configuration options can be set using Environment Variables:
1924
1925 baudrate - see CONFIG_BAUDRATE
1926
1927 bootdelay - see CONFIG_BOOTDELAY
1928
1929 bootcmd - see CONFIG_BOOTCOMMAND
1930
1931 bootargs - Boot arguments when booting an RTOS image
1932
1933 bootfile - Name of the image to load with TFTP
1934
1935 autoload - if set to "no" (any string beginning with 'n'),
1936 "bootp" will just load perform a lookup of the
1937 configuration from the BOOTP server, but not try to
1938 load any image using TFTP
1939
1940 autostart - if set to "yes", an image loaded using the "bootp",
1941 "rarpboot", "tftpboot" or "diskboot" commands will
1942 be automatically started (by internally calling
1943 "bootm")
1944
wdenk4a6fd342003-04-12 23:38:12 +00001945 If set to "no", a standalone image passed to the
1946 "bootm" command will be copied to the load address
1947 (and eventually uncompressed), but NOT be started.
1948 This can be used to load and uncompress arbitrary
1949 data.
1950
wdenkc6097192002-11-03 00:24:07 +00001951 initrd_high - restrict positioning of initrd images:
1952 If this variable is not set, initrd images will be
1953 copied to the highest possible address in RAM; this
1954 is usually what you want since it allows for
1955 maximum initrd size. If for some reason you want to
1956 make sure that the initrd image is loaded below the
1957 CFG_BOOTMAPSZ limit, you can set this environment
1958 variable to a value of "no" or "off" or "0".
1959 Alternatively, you can set it to a maximum upper
1960 address to use (U-Boot will still check that it
1961 does not overwrite the U-Boot stack and data).
1962
1963 For instance, when you have a system with 16 MB
1964 RAM, and want to reseve 4 MB from use by Linux,
1965 you can do this by adding "mem=12M" to the value of
1966 the "bootargs" variable. However, now you must make
1967 sure, that the initrd image is placed in the first
1968 12 MB as well - this can be done with
1969
1970 setenv initrd_high 00c00000
1971
1972 ipaddr - IP address; needed for tftpboot command
1973
1974 loadaddr - Default load address for commands like "bootp",
wdenkdc7c9a12003-03-26 06:55:25 +00001975 "rarpboot", "tftpboot", "loadb" or "diskboot"
wdenkc6097192002-11-03 00:24:07 +00001976
1977 loads_echo - see CONFIG_LOADS_ECHO
1978
1979 serverip - TFTP server IP address; needed for tftpboot command
1980
1981 bootretry - see CONFIG_BOOT_RETRY_TIME
1982
1983 bootdelaykey - see CONFIG_AUTOBOOT_DELAY_STR
1984
1985 bootstopkey - see CONFIG_AUTOBOOT_STOP_STR
1986
1987
1988The following environment variables may be used and automatically
1989updated by the network boot commands ("bootp" and "rarpboot"),
1990depending the information provided by your boot server:
1991
1992 bootfile - see above
1993 dnsip - IP address of your Domain Name Server
1994 gatewayip - IP address of the Gateway (Router) to use
1995 hostname - Target hostname
1996 ipaddr - see above
1997 netmask - Subnet Mask
1998 rootpath - Pathname of the root filesystem on the NFS server
1999 serverip - see above
2000
2001
2002There are two special Environment Variables:
2003
2004 serial# - contains hardware identification information such
2005 as type string and/or serial number
2006 ethaddr - Ethernet address
2007
2008These variables can be set only once (usually during manufacturing of
2009the board). U-Boot refuses to delete or overwrite these variables
2010once they have been set once.
2011
2012
stroesec1551ea2003-04-04 15:53:41 +00002013Further special Environment Variables:
2014
2015 ver - Contains the U-Boot version string as printed
2016 with the "version" command. This variable is
2017 readonly (see CONFIG_VERSION_VARIABLE).
2018
2019
wdenkc6097192002-11-03 00:24:07 +00002020Please note that changes to some configuration parameters may take
2021only effect after the next boot (yes, that's just like Windoze :-).
2022
2023
2024Note for Redundant Ethernet Interfaces:
2025=======================================
2026
2027Some boards come with redundand ethernet interfaces; U-Boot supports
2028such configurations and is capable of automatic selection of a
2029"working" interface when needed. MAC assignemnt works as follows:
2030
2031Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2032MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2033"eth1addr" (=>eth1), "eth2addr", ...
2034
2035If the network interface stores some valid MAC address (for instance
2036in SROM), this is used as default address if there is NO correspon-
2037ding setting in the environment; if the corresponding environment
2038variable is set, this overrides the settings in the card; that means:
2039
2040o If the SROM has a valid MAC address, and there is no address in the
2041 environment, the SROM's address is used.
2042
2043o If there is no valid address in the SROM, and a definition in the
2044 environment exists, then the value from the environment variable is
2045 used.
2046
2047o If both the SROM and the environment contain a MAC address, and
2048 both addresses are the same, this MAC address is used.
2049
2050o If both the SROM and the environment contain a MAC address, and the
2051 addresses differ, the value from the environment is used and a
2052 warning is printed.
2053
2054o If neither SROM nor the environment contain a MAC address, an error
2055 is raised.
2056
2057
2058
2059Image Formats:
2060==============
2061
2062The "boot" commands of this monitor operate on "image" files which
2063can be basicly anything, preceeded by a special header; see the
2064definitions in include/image.h for details; basicly, the header
2065defines the following image properties:
2066
2067* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2068 4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2069 LynxOS, pSOS, QNX;
2070 Currently supported: Linux, NetBSD, VxWorks, QNX).
2071* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2072 IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2073 Currently supported: PowerPC).
2074* Compression Type (Provisions for uncompressed, gzip, bzip2;
2075 Currently supported: uncompressed, gzip).
2076* Load Address
2077* Entry Point
2078* Image Name
2079* Image Timestamp
2080
2081The header is marked by a special Magic Number, and both the header
2082and the data portions of the image are secured against corruption by
2083CRC32 checksums.
2084
2085
2086Linux Support:
2087==============
2088
2089Although U-Boot should support any OS or standalone application
2090easily, Linux has always been in the focus during the design of
2091U-Boot.
2092
2093U-Boot includes many features that so far have been part of some
2094special "boot loader" code within the Linux kernel. Also, any
2095"initrd" images to be used are no longer part of one big Linux image;
2096instead, kernel and "initrd" are separate images. This implementation
2097serves serveral purposes:
2098
2099- the same features can be used for other OS or standalone
2100 applications (for instance: using compressed images to reduce the
2101 Flash memory footprint)
2102
2103- it becomes much easier to port new Linux kernel versions because
2104 lots of low-level, hardware dependend stuff are done by U-Boot
2105
2106- the same Linux kernel image can now be used with different "initrd"
2107 images; of course this also means that different kernel images can
2108 be run with the same "initrd". This makes testing easier (you don't
2109 have to build a new "zImage.initrd" Linux image when you just
2110 change a file in your "initrd"). Also, a field-upgrade of the
2111 software is easier now.
2112
2113
2114Linux HOWTO:
2115============
2116
2117Porting Linux to U-Boot based systems:
2118---------------------------------------
2119
2120U-Boot cannot save you from doing all the necessary modifications to
2121configure the Linux device drivers for use with your target hardware
2122(no, we don't intend to provide a full virtual machine interface to
2123Linux :-).
2124
2125But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2126
2127Just make sure your machine specific header file (for instance
2128include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2129Information structure as we define in include/u-boot.h, and make
2130sure that your definition of IMAP_ADDR uses the same value as your
2131U-Boot configuration in CFG_IMMR.
2132
2133
2134Configuring the Linux kernel:
2135-----------------------------
2136
2137No specific requirements for U-Boot. Make sure you have some root
2138device (initial ramdisk, NFS) for your target system.
2139
2140
2141Building a Linux Image:
2142-----------------------
2143
wdenk24ee89b2002-11-03 17:56:27 +00002144With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2145not used. If you use recent kernel source, a new build target
2146"uImage" will exist which automatically builds an image usable by
2147U-Boot. Most older kernels also have support for a "pImage" target,
2148which was introduced for our predecessor project PPCBoot and uses a
2149100% compatible format.
wdenkc6097192002-11-03 00:24:07 +00002150
2151Example:
2152
2153 make TQM850L_config
2154 make oldconfig
2155 make dep
wdenk24ee89b2002-11-03 17:56:27 +00002156 make uImage
wdenkc6097192002-11-03 00:24:07 +00002157
wdenk24ee89b2002-11-03 17:56:27 +00002158The "uImage" build target uses a special tool (in 'tools/mkimage') to
2159encapsulate a compressed Linux kernel image with header information,
2160CRC32 checksum etc. for use with U-Boot. This is what we are doing:
wdenkc6097192002-11-03 00:24:07 +00002161
wdenk24ee89b2002-11-03 17:56:27 +00002162* build a standard "vmlinux" kernel image (in ELF binary format):
wdenkc6097192002-11-03 00:24:07 +00002163
wdenk24ee89b2002-11-03 17:56:27 +00002164* convert the kernel into a raw binary image:
2165
2166 ${CROSS_COMPILE}-objcopy -O binary \
2167 -R .note -R .comment \
2168 -S vmlinux linux.bin
2169
2170* compress the binary image:
2171
2172 gzip -9 linux.bin
2173
2174* package compressed binary image for U-Boot:
2175
2176 mkimage -A ppc -O linux -T kernel -C gzip \
2177 -a 0 -e 0 -n "Linux Kernel Image" \
2178 -d linux.bin.gz uImage
2179
2180
2181The "mkimage" tool can also be used to create ramdisk images for use
2182with U-Boot, either separated from the Linux kernel image, or
2183combined into one file. "mkimage" encapsulates the images with a 64
2184byte header containing information about target architecture,
2185operating system, image type, compression method, entry points, time
2186stamp, CRC32 checksums, etc.
2187
2188"mkimage" can be called in two ways: to verify existing images and
2189print the header information, or to build new images.
2190
2191In the first form (with "-l" option) mkimage lists the information
2192contained in the header of an existing U-Boot image; this includes
wdenkc6097192002-11-03 00:24:07 +00002193checksum verification:
2194
2195 tools/mkimage -l image
2196 -l ==> list image header information
2197
2198The second form (with "-d" option) is used to build a U-Boot image
2199from a "data file" which is used as image payload:
2200
2201 tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2202 -n name -d data_file image
2203 -A ==> set architecture to 'arch'
2204 -O ==> set operating system to 'os'
2205 -T ==> set image type to 'type'
2206 -C ==> set compression type 'comp'
2207 -a ==> set load address to 'addr' (hex)
2208 -e ==> set entry point to 'ep' (hex)
2209 -n ==> set image name to 'name'
2210 -d ==> use image data from 'datafile'
2211
2212Right now, all Linux kernels use the same load address (0x00000000),
2213but the entry point address depends on the kernel version:
2214
2215- 2.2.x kernels have the entry point at 0x0000000C,
wdenk24ee89b2002-11-03 17:56:27 +00002216- 2.3.x and later kernels have the entry point at 0x00000000.
wdenkc6097192002-11-03 00:24:07 +00002217
2218So a typical call to build a U-Boot image would read:
2219
wdenk24ee89b2002-11-03 17:56:27 +00002220 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2221 > -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2222 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2223 > examples/uImage.TQM850L
2224 Image Name: 2.4.4 kernel for TQM850L
wdenkc6097192002-11-03 00:24:07 +00002225 Created: Wed Jul 19 02:34:59 2000
2226 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2227 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2228 Load Address: 0x00000000
wdenk24ee89b2002-11-03 17:56:27 +00002229 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002230
2231To verify the contents of the image (or check for corruption):
2232
wdenk24ee89b2002-11-03 17:56:27 +00002233 -> tools/mkimage -l examples/uImage.TQM850L
2234 Image Name: 2.4.4 kernel for TQM850L
wdenkc6097192002-11-03 00:24:07 +00002235 Created: Wed Jul 19 02:34:59 2000
2236 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2237 Data Size: 335725 Bytes = 327.86 kB = 0.32 MB
2238 Load Address: 0x00000000
wdenk24ee89b2002-11-03 17:56:27 +00002239 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002240
2241NOTE: for embedded systems where boot time is critical you can trade
2242speed for memory and install an UNCOMPRESSED image instead: this
2243needs more space in Flash, but boots much faster since it does not
2244need to be uncompressed:
2245
wdenk24ee89b2002-11-03 17:56:27 +00002246 -> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2247 -> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2248 > -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2249 > -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2250 > examples/uImage.TQM850L-uncompressed
2251 Image Name: 2.4.4 kernel for TQM850L
wdenkc6097192002-11-03 00:24:07 +00002252 Created: Wed Jul 19 02:34:59 2000
2253 Image Type: PowerPC Linux Kernel Image (uncompressed)
2254 Data Size: 792160 Bytes = 773.59 kB = 0.76 MB
2255 Load Address: 0x00000000
wdenk24ee89b2002-11-03 17:56:27 +00002256 Entry Point: 0x00000000
wdenkc6097192002-11-03 00:24:07 +00002257
2258
2259Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2260when your kernel is intended to use an initial ramdisk:
2261
2262 -> tools/mkimage -n 'Simple Ramdisk Image' \
2263 > -A ppc -O linux -T ramdisk -C gzip \
2264 > -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2265 Image Name: Simple Ramdisk Image
2266 Created: Wed Jan 12 14:01:50 2000
2267 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2268 Data Size: 566530 Bytes = 553.25 kB = 0.54 MB
2269 Load Address: 0x00000000
2270 Entry Point: 0x00000000
2271
2272
2273Installing a Linux Image:
2274-------------------------
2275
2276To downloading a U-Boot image over the serial (console) interface,
2277you must convert the image to S-Record format:
2278
2279 objcopy -I binary -O srec examples/image examples/image.srec
2280
2281The 'objcopy' does not understand the information in the U-Boot
2282image header, so the resulting S-Record file will be relative to
2283address 0x00000000. To load it to a given address, you need to
2284specify the target address as 'offset' parameter with the 'loads'
2285command.
2286
2287Example: install the image to address 0x40100000 (which on the
2288TQM8xxL is in the first Flash bank):
2289
2290 => erase 40100000 401FFFFF
2291
2292 .......... done
2293 Erased 8 sectors
2294
2295 => loads 40100000
2296 ## Ready for S-Record download ...
2297 ~>examples/image.srec
2298 1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2299 ...
2300 15989 15990 15991 15992
2301 [file transfer complete]
2302 [connected]
2303 ## Start Addr = 0x00000000
2304
2305
2306You can check the success of the download using the 'iminfo' command;
2307this includes a checksum verification so you can be sure no data
2308corruption happened:
2309
2310 => imi 40100000
2311
2312 ## Checking Image at 40100000 ...
2313 Image Name: 2.2.13 for initrd on TQM850L
2314 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2315 Data Size: 335725 Bytes = 327 kB = 0 MB
2316 Load Address: 00000000
2317 Entry Point: 0000000c
2318 Verifying Checksum ... OK
2319
2320
2321
2322Boot Linux:
2323-----------
2324
2325The "bootm" command is used to boot an application that is stored in
2326memory (RAM or Flash). In case of a Linux kernel image, the contents
2327of the "bootargs" environment variable is passed to the kernel as
2328parameters. You can check and modify this variable using the
2329"printenv" and "setenv" commands:
2330
2331
2332 => printenv bootargs
2333 bootargs=root=/dev/ram
2334
2335 => setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2336
2337 => printenv bootargs
2338 bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2339
2340 => bootm 40020000
2341 ## Booting Linux kernel at 40020000 ...
2342 Image Name: 2.2.13 for NFS on TQM850L
2343 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2344 Data Size: 381681 Bytes = 372 kB = 0 MB
2345 Load Address: 00000000
2346 Entry Point: 0000000c
2347 Verifying Checksum ... OK
2348 Uncompressing Kernel Image ... OK
2349 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
2350 Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2351 time_init: decrementer frequency = 187500000/60
2352 Calibrating delay loop... 49.77 BogoMIPS
2353 Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2354 ...
2355
2356If you want to boot a Linux kernel with initial ram disk, you pass
2357the memory addreses of both the kernel and the initrd image (PPBCOOT
2358format!) to the "bootm" command:
2359
2360 => imi 40100000 40200000
2361
2362 ## Checking Image at 40100000 ...
2363 Image Name: 2.2.13 for initrd on TQM850L
2364 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2365 Data Size: 335725 Bytes = 327 kB = 0 MB
2366 Load Address: 00000000
2367 Entry Point: 0000000c
2368 Verifying Checksum ... OK
2369
2370 ## Checking Image at 40200000 ...
2371 Image Name: Simple Ramdisk Image
2372 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2373 Data Size: 566530 Bytes = 553 kB = 0 MB
2374 Load Address: 00000000
2375 Entry Point: 00000000
2376 Verifying Checksum ... OK
2377
2378 => bootm 40100000 40200000
2379 ## Booting Linux kernel at 40100000 ...
2380 Image Name: 2.2.13 for initrd on TQM850L
2381 Image Type: PowerPC Linux Kernel Image (gzip compressed)
2382 Data Size: 335725 Bytes = 327 kB = 0 MB
2383 Load Address: 00000000
2384 Entry Point: 0000000c
2385 Verifying Checksum ... OK
2386 Uncompressing Kernel Image ... OK
2387 ## Loading RAMDisk Image at 40200000 ...
2388 Image Name: Simple Ramdisk Image
2389 Image Type: PowerPC Linux RAMDisk Image (gzip compressed)
2390 Data Size: 566530 Bytes = 553 kB = 0 MB
2391 Load Address: 00000000
2392 Entry Point: 00000000
2393 Verifying Checksum ... OK
2394 Loading Ramdisk ... OK
2395 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
2396 Boot arguments: root=/dev/ram
2397 time_init: decrementer frequency = 187500000/60
2398 Calibrating delay loop... 49.77 BogoMIPS
2399 ...
2400 RAMDISK: Compressed image found at block 0
2401 VFS: Mounted root (ext2 filesystem).
2402
2403 bash#
2404
wdenk6069ff22003-02-28 00:49:47 +00002405More About U-Boot Image Types:
2406------------------------------
2407
2408U-Boot supports the following image types:
2409
2410 "Standalone Programs" are directly runnable in the environment
2411 provided by U-Boot; it is expected that (if they behave
2412 well) you can continue to work in U-Boot after return from
2413 the Standalone Program.
2414 "OS Kernel Images" are usually images of some Embedded OS which
2415 will take over control completely. Usually these programs
2416 will install their own set of exception handlers, device
2417 drivers, set up the MMU, etc. - this means, that you cannot
2418 expect to re-enter U-Boot except by resetting the CPU.
2419 "RAMDisk Images" are more or less just data blocks, and their
2420 parameters (address, size) are passed to an OS kernel that is
2421 being started.
2422 "Multi-File Images" contain several images, typically an OS
2423 (Linux) kernel image and one or more data images like
2424 RAMDisks. This construct is useful for instance when you want
2425 to boot over the network using BOOTP etc., where the boot
2426 server provides just a single image file, but you want to get
2427 for instance an OS kernel and a RAMDisk image.
stroesec1551ea2003-04-04 15:53:41 +00002428
wdenk6069ff22003-02-28 00:49:47 +00002429 "Multi-File Images" start with a list of image sizes, each
2430 image size (in bytes) specified by an "uint32_t" in network
2431 byte order. This list is terminated by an "(uint32_t)0".
2432 Immediately after the terminating 0 follow the images, one by
2433 one, all aligned on "uint32_t" boundaries (size rounded up to
2434 a multiple of 4 bytes).
stroesec1551ea2003-04-04 15:53:41 +00002435
wdenk6069ff22003-02-28 00:49:47 +00002436 "Firmware Images" are binary images containing firmware (like
2437 U-Boot or FPGA images) which usually will be programmed to
2438 flash memory.
stroesec1551ea2003-04-04 15:53:41 +00002439
wdenk6069ff22003-02-28 00:49:47 +00002440 "Script files" are command sequences that will be executed by
2441 U-Boot's command interpreter; this feature is especially
2442 useful when you configure U-Boot to use a real shell (hush)
2443 as command interpreter.
2444
wdenkc6097192002-11-03 00:24:07 +00002445
2446Standalone HOWTO:
2447=================
2448
2449One of the features of U-Boot is that you can dynamically load and
2450run "standalone" applications, which can use some resources of
2451U-Boot like console I/O functions or interrupt services.
2452
2453Two simple examples are included with the sources:
2454
2455"Hello World" Demo:
2456-------------------
2457
2458'examples/hello_world.c' contains a small "Hello World" Demo
2459application; it is automatically compiled when you build U-Boot.
2460It's configured to run at address 0x00040004, so you can play with it
2461like that:
2462
2463 => loads
2464 ## Ready for S-Record download ...
2465 ~>examples/hello_world.srec
2466 1 2 3 4 5 6 7 8 9 10 11 ...
2467 [file transfer complete]
2468 [connected]
2469 ## Start Addr = 0x00040004
2470
2471 => go 40004 Hello World! This is a test.
2472 ## Starting application at 0x00040004 ...
2473 Hello World
2474 argc = 7
2475 argv[0] = "40004"
2476 argv[1] = "Hello"
2477 argv[2] = "World!"
2478 argv[3] = "This"
2479 argv[4] = "is"
2480 argv[5] = "a"
2481 argv[6] = "test."
2482 argv[7] = "<NULL>"
2483 Hit any key to exit ...
2484
2485 ## Application terminated, rc = 0x0
2486
2487Another example, which demonstrates how to register a CPM interrupt
2488handler with the U-Boot code, can be found in 'examples/timer.c'.
2489Here, a CPM timer is set up to generate an interrupt every second.
2490The interrupt service routine is trivial, just printing a '.'
2491character, but this is just a demo program. The application can be
2492controlled by the following keys:
2493
2494 ? - print current values og the CPM Timer registers
2495 b - enable interrupts and start timer
2496 e - stop timer and disable interrupts
2497 q - quit application
2498
2499 => loads
2500 ## Ready for S-Record download ...
2501 ~>examples/timer.srec
2502 1 2 3 4 5 6 7 8 9 10 11 ...
2503 [file transfer complete]
2504 [connected]
2505 ## Start Addr = 0x00040004
2506
2507 => go 40004
2508 ## Starting application at 0x00040004 ...
2509 TIMERS=0xfff00980
2510 Using timer 1
2511 tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2512
2513Hit 'b':
2514 [q, b, e, ?] Set interval 1000000 us
2515 Enabling timer
2516Hit '?':
2517 [q, b, e, ?] ........
2518 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2519Hit '?':
2520 [q, b, e, ?] .
2521 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2522Hit '?':
2523 [q, b, e, ?] .
2524 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2525Hit '?':
2526 [q, b, e, ?] .
2527 tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2528Hit 'e':
2529 [q, b, e, ?] ...Stopping timer
2530Hit 'q':
2531 [q, b, e, ?] ## Application terminated, rc = 0x0
2532
2533
wdenk85ec0bc2003-03-31 16:34:49 +00002534
2535Minicom warning:
2536================
2537
2538Over time, many people have reported problems when trying to used the
2539"minicom" terminal emulation program for serial download. I (wd)
2540consider minicom to be broken, and recommend not to use it. Under
2541Unix, I recommend to use CKermit for general purpose use (and
2542especially for kermit binary protocol download ("loadb" command), and
2543use "cu" for S-Record download ("loads" command).
2544
wdenkc6097192002-11-03 00:24:07 +00002545NetBSD Notes:
2546=============
2547
2548Starting at version 0.9.2, U-Boot supports NetBSD both as host
2549(build U-Boot) and target system (boots NetBSD/mpc8xx).
2550
2551Building requires a cross environment; it is known to work on
2552NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2553need gmake since the Makefiles are not compatible with BSD make).
2554Note that the cross-powerpc package does not install include files;
2555attempting to build U-Boot will fail because <machine/ansi.h> is
2556missing. This file has to be installed and patched manually:
2557
2558 # cd /usr/pkg/cross/powerpc-netbsd/include
2559 # mkdir powerpc
2560 # ln -s powerpc machine
2561 # cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2562 # ${EDIT} powerpc/ansi.h ## must remove __va_list, _BSD_VA_LIST
2563
2564Native builds *don't* work due to incompatibilities between native
2565and U-Boot include files.
2566
2567Booting assumes that (the first part of) the image booted is a
2568stage-2 loader which in turn loads and then invokes the kernel
2569proper. Loader sources will eventually appear in the NetBSD source
2570tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2571meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2572details.
2573
2574
2575Implementation Internals:
2576=========================
2577
2578The following is not intended to be a complete description of every
2579implementation detail. However, it should help to understand the
2580inner workings of U-Boot and make it easier to port it to custom
2581hardware.
2582
2583
2584Initial Stack, Global Data:
2585---------------------------
2586
2587The implementation of U-Boot is complicated by the fact that U-Boot
2588starts running out of ROM (flash memory), usually without access to
2589system RAM (because the memory controller is not initialized yet).
2590This means that we don't have writable Data or BSS segments, and BSS
2591is not initialized as zero. To be able to get a C environment working
2592at all, we have to allocate at least a minimal stack. Implementation
2593options for this are defined and restricted by the CPU used: Some CPU
2594models provide on-chip memory (like the IMMR area on MPC8xx and
2595MPC826x processors), on others (parts of) the data cache can be
2596locked as (mis-) used as memory, etc.
2597
wdenk43d96162003-03-06 00:02:04 +00002598 Chris Hallinan posted a good summy of these issues to the
2599 u-boot-users mailing list:
2600
2601 Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2602 From: "Chris Hallinan" <clh@net1plus.com>
2603 Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2604 ...
2605
2606 Correct me if I'm wrong, folks, but the way I understand it
2607 is this: Using DCACHE as initial RAM for Stack, etc, does not
2608 require any physical RAM backing up the cache. The cleverness
2609 is that the cache is being used as a temporary supply of
2610 necessary storage before the SDRAM controller is setup. It's
2611 beyond the scope of this list to expain the details, but you
2612 can see how this works by studying the cache architecture and
2613 operation in the architecture and processor-specific manuals.
2614
2615 OCM is On Chip Memory, which I believe the 405GP has 4K. It
2616 is another option for the system designer to use as an
2617 initial stack/ram area prior to SDRAM being available. Either
2618 option should work for you. Using CS 4 should be fine if your
2619 board designers haven't used it for something that would
2620 cause you grief during the initial boot! It is frequently not
2621 used.
2622
2623 CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2624 with your processor/board/system design. The default value
2625 you will find in any recent u-boot distribution in
2626 Walnut405.h should work for you. I'd set it to a value larger
2627 than your SDRAM module. If you have a 64MB SDRAM module, set
2628 it above 400_0000. Just make sure your board has no resources
2629 that are supposed to respond to that address! That code in
2630 start.S has been around a while and should work as is when
2631 you get the config right.
2632
2633 -Chris Hallinan
2634 DS4.COM, Inc.
2635
wdenkc6097192002-11-03 00:24:07 +00002636It is essential to remember this, since it has some impact on the C
2637code for the initialization procedures:
2638
2639* Initialized global data (data segment) is read-only. Do not attempt
2640 to write it.
2641
2642* Do not use any unitialized global data (or implicitely initialized
2643 as zero data - BSS segment) at all - this is undefined, initiali-
2644 zation is performed later (when relocationg to RAM).
2645
2646* Stack space is very limited. Avoid big data buffers or things like
2647 that.
2648
2649Having only the stack as writable memory limits means we cannot use
2650normal global data to share information beween the code. But it
2651turned out that the implementation of U-Boot can be greatly
2652simplified by making a global data structure (gd_t) available to all
2653functions. We could pass a pointer to this data as argument to _all_
2654functions, but this would bloat the code. Instead we use a feature of
2655the GCC compiler (Global Register Variables) to share the data: we
2656place a pointer (gd) to the global data into a register which we
2657reserve for this purpose.
2658
2659When chosing a register for such a purpose we are restricted by the
2660relevant (E)ABI specifications for the current architecture, and by
2661GCC's implementation.
2662
2663For PowerPC, the following registers have specific use:
2664 R1: stack pointer
2665 R2: TOC pointer
2666 R3-R4: parameter passing and return values
2667 R5-R10: parameter passing
2668 R13: small data area pointer
2669 R30: GOT pointer
2670 R31: frame pointer
2671
2672 (U-Boot also uses R14 as internal GOT pointer.)
2673
2674 ==> U-Boot will use R29 to hold a pointer to the global data
2675
2676 Note: on PPC, we could use a static initializer (since the
2677 address of the global data structure is known at compile time),
2678 but it turned out that reserving a register results in somewhat
2679 smaller code - although the code savings are not that big (on
2680 average for all boards 752 bytes for the whole U-Boot image,
2681 624 text + 127 data).
2682
2683On ARM, the following registers are used:
2684
2685 R0: function argument word/integer result
2686 R1-R3: function argument word
2687 R9: GOT pointer
2688 R10: stack limit (used only if stack checking if enabled)
2689 R11: argument (frame) pointer
2690 R12: temporary workspace
2691 R13: stack pointer
2692 R14: link register
2693 R15: program counter
2694
2695 ==> U-Boot will use R8 to hold a pointer to the global data
2696
2697
2698
2699Memory Management:
2700------------------
2701
2702U-Boot runs in system state and uses physical addresses, i.e. the
2703MMU is not used either for address mapping nor for memory protection.
2704
2705The available memory is mapped to fixed addresses using the memory
2706controller. In this process, a contiguous block is formed for each
2707memory type (Flash, SDRAM, SRAM), even when it consists of several
2708physical memory banks.
2709
2710U-Boot is installed in the first 128 kB of the first Flash bank (on
2711TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2712booting and sizing and initializing DRAM, the code relocates itself
2713to the upper end of DRAM. Immediately below the U-Boot code some
2714memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2715configuration setting]. Below that, a structure with global Board
2716Info data is placed, followed by the stack (growing downward).
2717
2718Additionally, some exception handler code is copied to the low 8 kB
2719of DRAM (0x00000000 ... 0x00001FFF).
2720
2721So a typical memory configuration with 16 MB of DRAM could look like
2722this:
2723
2724 0x0000 0000 Exception Vector code
2725 :
2726 0x0000 1FFF
2727 0x0000 2000 Free for Application Use
2728 :
2729 :
2730
2731 :
2732 :
2733 0x00FB FF20 Monitor Stack (Growing downward)
2734 0x00FB FFAC Board Info Data and permanent copy of global data
2735 0x00FC 0000 Malloc Arena
2736 :
2737 0x00FD FFFF
2738 0x00FE 0000 RAM Copy of Monitor Code
2739 ... eventually: LCD or video framebuffer
2740 ... eventually: pRAM (Protected RAM - unchanged by reset)
2741 0x00FF FFFF [End of RAM]
2742
2743
2744System Initialization:
2745----------------------
2746
2747In the reset configuration, U-Boot starts at the reset entry point
2748(on most PowerPC systens at address 0x00000100). Because of the reset
2749configuration for CS0# this is a mirror of the onboard Flash memory.
2750To be able to re-map memory U-Boot then jumps to it's link address.
2751To be able to implement the initialization code in C, a (small!)
2752initial stack is set up in the internal Dual Ported RAM (in case CPUs
2753which provide such a feature like MPC8xx or MPC8260), or in a locked
2754part of the data cache. After that, U-Boot initializes the CPU core,
2755the caches and the SIU.
2756
2757Next, all (potentially) available memory banks are mapped using a
2758preliminary mapping. For example, we put them on 512 MB boundaries
2759(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2760on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2761programmed for SDRAM access. Using the temporary configuration, a
2762simple memory test is run that determines the size of the SDRAM
2763banks.
2764
2765When there is more than one SDRAM bank, and the banks are of
2766different size, the larger is mapped first. For equal size, the first
2767bank (CS2#) is mapped first. The first mapping is always for address
27680x00000000, with any additional banks following immediately to create
2769contiguous memory starting from 0.
2770
2771Then, the monitor installs itself at the upper end of the SDRAM area
2772and allocates memory for use by malloc() and for the global Board
2773Info data; also, the exception vector code is copied to the low RAM
2774pages, and the final stack is set up.
2775
2776Only after this relocation will you have a "normal" C environment;
2777until that you are restricted in several ways, mostly because you are
2778running from ROM, and because the code will have to be relocated to a
2779new address in RAM.
2780
2781
2782U-Boot Porting Guide:
2783----------------------
2784
2785[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
wdenk6aff3112002-12-17 01:51:00 +00002786list, October 2002]
wdenkc6097192002-11-03 00:24:07 +00002787
2788
2789int main (int argc, char *argv[])
2790{
2791 sighandler_t no_more_time;
2792
2793 signal (SIGALRM, no_more_time);
2794 alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2795
2796 if (available_money > available_manpower) {
2797 pay consultant to port U-Boot;
2798 return 0;
2799 }
2800
2801 Download latest U-Boot source;
2802
wdenk6aff3112002-12-17 01:51:00 +00002803 Subscribe to u-boot-users mailing list;
2804
wdenkc6097192002-11-03 00:24:07 +00002805 if (clueless) {
2806 email ("Hi, I am new to U-Boot, how do I get started?");
2807 }
2808
2809 while (learning) {
2810 Read the README file in the top level directory;
2811 Read http://www.denx.de/re/DPLG.html
2812 Read the source, Luke;
2813 }
2814
2815 if (available_money > toLocalCurrency ($2500)) {
2816 Buy a BDI2000;
2817 } else {
2818 Add a lot of aggravation and time;
2819 }
2820
2821 Create your own board support subdirectory;
2822
wdenk6aff3112002-12-17 01:51:00 +00002823 Create your own board config file;
2824
wdenkc6097192002-11-03 00:24:07 +00002825 while (!running) {
2826 do {
2827 Add / modify source code;
2828 } until (compiles);
2829 Debug;
2830 if (clueless)
2831 email ("Hi, I am having problems...");
2832 }
2833 Send patch file to Wolfgang;
2834
2835 return 0;
2836}
2837
2838void no_more_time (int sig)
2839{
2840 hire_a_guru();
2841}
2842
2843
2844
2845Coding Standards:
2846-----------------
2847
2848All contributions to U-Boot should conform to the Linux kernel
2849coding style; see the file "Documentation/CodingStyle" in your Linux
2850kernel source directory.
2851
2852Please note that U-Boot is implemented in C (and to some small parts
2853in Assembler); no C++ is used, so please do not use C++ style
2854comments (//) in your code.
2855
2856Submissions which do not conform to the standards may be returned
2857with a request to reformat the changes.
2858
2859
2860Submitting Patches:
2861-------------------
2862
2863Since the number of patches for U-Boot is growing, we need to
2864establish some rules. Submissions which do not conform to these rules
2865may be rejected, even when they contain important and valuable stuff.
2866
2867
2868When you send a patch, please include the following information with
2869it:
2870
2871* For bug fixes: a description of the bug and how your patch fixes
2872 this bug. Please try to include a way of demonstrating that the
2873 patch actually fixes something.
2874
2875* For new features: a description of the feature and your
2876 implementation.
2877
2878* A CHANGELOG entry as plaintext (separate from the patch)
2879
2880* For major contributions, your entry to the CREDITS file
2881
2882* When you add support for a new board, don't forget to add this
2883 board to the MAKEALL script, too.
2884
2885* If your patch adds new configuration options, don't forget to
2886 document these in the README file.
2887
2888* The patch itself. If you are accessing the CVS repository use "cvs
2889 update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
2890 version of diff does not support these options, then get the latest
2891 version of GNU diff.
2892
2893 We accept patches as plain text, MIME attachments or as uuencoded
2894 gzipped text.
2895
2896Notes:
2897
2898* Before sending the patch, run the MAKEALL script on your patched
2899 source tree and make sure that no errors or warnings are reported
2900 for any of the boards.
2901
2902* Keep your modifications to the necessary minimum: A patch
2903 containing several unrelated changes or arbitrary reformats will be
2904 returned with a request to re-formatting / split it.
2905
2906* If you modify existing code, make sure that your new code does not
2907 add to the memory footprint of the code ;-) Small is beautiful!
2908 When adding new features, these should compile conditionally only
2909 (using #ifdef), and the resulting code with the new feature
2910 disabled must not need more memory than the old code without your
2911 modification.