xref: /openbmc/u-boot/README (revision 6dd652fa4d8591a32e2707a91f4582ed13011b17)
1#
2# (C) Copyright 2000 - 2002
3# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4#
5# See file CREDITS for list of people who contributed to this
6# project.
7#
8# This program is free software; you can redistribute it and/or
9# modify it under the terms of the GNU General Public License as
10# published by the Free Software Foundation; either version 2 of
11# the License, or (at your option) any later version.
12#
13# This program is distributed in the hope that it will be useful,
14# but WITHOUT ANY WARRANTY; without even the implied warranty of
15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
16# GNU General Public License for more details.
17#
18# You should have received a copy of the GNU General Public License
19# along with this program; if not, write to the Free Software
20# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21# MA 02111-1307 USA
22#
23
24Summary:
25========
26
27This 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.
31
32The development of U-Boot is closely related to Linux: some parts of
33the source code originate in the Linux source tree, we have some
34header files in common, and special provision has been made to
35support 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
49Makefile have been tested to some extent and can be considered
50"working". In fact, many of them are used in production systems.
51
52In case of problems see the CHANGELOG and CREDITS files to find out
53who contributed the specific port.
54
55
56Where to get help:
57==================
58
59In 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
63before 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
71- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
72- clean up code
73- make it easier to add custom boards
74- make it possible to add other [PowerPC] CPUs
75- extend functions, especially:
76  * Provide extended interface to Linux boot loader
77  * S-Record download
78  * network boot
79  * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
80- create ARMBoot project (http://sourceforge.net/projects/armboot)
81- add other CPU families (starting with ARM)
82- create U-Boot project (http://sourceforge.net/projects/u-boot)
83
84
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
105
106
107Versioning:
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
119Directory 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
143- cpu/mpc5xx	Files specific to Motorola MPC5xx  CPUs
144- 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
149- board/LEOX/   Files specific to boards manufactured by The LEOX team
150- board/LEOX/elpt860	Files specific to ELPT860 boards
151- board/RPXClassic
152		Files specific to RPXClassic boards
153- board/RPXlite	Files specific to RPXlite    boards
154- board/at91rm9200dk Files specific to AT91RM9200DK boards
155- board/c2mon	Files specific to c2mon	     boards
156- board/cmi	Files specific to cmi        boards
157- board/cogent	Files specific to Cogent     boards
158		(need further configuration)
159		Files specific to CPCIISER4  boards
160- board/cpu86	Files specific to CPU86      boards
161- board/cray/	Files specific to boards manufactured by Cray
162- board/cray/L1		Files specific to L1         boards
163- board/cu824	Files specific to CU824	     boards
164- board/ebony   Files specific to IBM Ebony board
165- board/eric	Files specific to ERIC	     boards
166- board/esd/	Files specific to boards manufactured by ESD
167- board/esd/adciop	Files specific to ADCIOP     boards
168- board/esd/ar405	Files specific to AR405	     boards
169- board/esd/canbt	Files specific to CANBT	     boards
170- board/esd/cpci405	Files specific to CPCI405    boards
171- board/esd/cpciiser4	Files specific to CPCIISER4  boards
172- board/esd/common	Common files for ESD boards
173- board/esd/dasa_sim	Files specific to DASA_SIM   boards
174- board/esd/du405	Files specific to DU405      boards
175- board/esd/ocrtc	Files specific to OCRTC      boards
176- board/esd/pci405	Files specific to PCI405     boards
177- board/esteem192e
178		Files specific to ESTEEM192E boards
179- board/etx094	Files specific to ETX_094    boards
180- board/evb64260
181		Files specific to EVB64260   boards
182- board/fads	Files specific to FADS	     boards
183- board/flagadm Files specific to FLAGADM    boards
184- board/gen860t Files specific to GEN860T and GEN860T_SC    boards
185- board/genietv Files specific to GENIETV    boards
186- board/gth	Files specific to GTH	     boards
187- board/hermes	Files specific to HERMES     boards
188- board/hymod	Files specific to HYMOD	     boards
189- board/icu862	Files specific to ICU862     boards
190- board/ip860	Files specific to IP860	     boards
191- board/iphase4539
192		Files specific to Interphase4539 boards
193- board/ivm	Files specific to IVMS8/IVML24 boards
194- board/lantec	Files specific to LANTEC     boards
195- board/lwmon	Files specific to LWMON	     boards
196- board/mbx8xx	Files specific to MBX	     boards
197- board/mpc8260ads
198		Files specific to MMPC8260ADS boards
199- board/mpl/	Files specific to boards manufactured by MPL
200- board/mpl/common	Common files for MPL boards
201- board/mpl/pip405	Files specific to PIP405     boards
202- board/mpl/mip405	Files specific to MIP405     boards
203- board/musenki	Files specific to MUSEKNI    boards
204- board/mvs1	Files specific to MVS1       boards
205- board/nx823   Files specific to NX823      boards
206- board/oxc	Files specific to OXC        boards
207- board/pcippc2	Files specific to PCIPPC2/PCIPPC6 boards
208- board/pm826	Files specific to PM826      boards
209- board/ppmc8260
210		Files specific to PPMC8260   boards
211- board/rpxsuper
212		Files specific to RPXsuper   boards
213- board/rsdproto
214		Files specific to RSDproto   boards
215- board/sandpoint
216		Files specific to Sandpoint  boards
217- board/sbc8260	Files specific to SBC8260    boards
218- board/sacsng	Files specific to SACSng     boards
219- board/siemens Files specific to boards manufactured by Siemens AG
220- board/siemens/CCM	Files specific to CCM	     boards
221- board/siemens/IAD210	Files specific to IAD210     boards
222- board/siemens/SCM	Files specific to SCM        boards
223- board/siemens/pcu_e	Files specific to PCU_E	     boards
224- board/sixnet	Files specific to SIXNET     boards
225- board/spd8xx	Files specific to SPD8xxTS   boards
226- board/tqm8260 Files specific to TQM8260    boards
227- board/tqm8xx	Files specific to TQM8xxL    boards
228- board/w7o	Files specific to W7O        boards
229- board/walnut405
230		Files specific to Walnut405  boards
231- board/westel/	Files specific to boards manufactured by Westel Wireless
232- board/westel/amx860	Files specific to AMX860     boards
233- board/utx8245	Files specific to UTX8245   boards
234
235Software Configuration:
236=======================
237
238Configuration is usually done using C preprocessor defines; the
239rationale behind that is to avoid dead code whenever possible.
240
241There are two classes of configuration variables:
242
243* Configuration _OPTIONS_:
244  These are selectable by the user and have names beginning with
245  "CONFIG_".
246
247* Configuration _SETTINGS_:
248  These depend on the hardware etc. and should not be meddled with if
249  you don't know what you're doing; they have names beginning with
250  "CFG_".
251
252Later we will add a configuration tool - probably similar to or even
253identical to what's used for the Linux kernel. Right now, we have to
254do the configuration by hand, which means creating some symbolic
255links and editing some configuration files. We use the TQM8xxL boards
256as an example here.
257
258
259Selection of Processor Architecture and Board Type:
260---------------------------------------------------
261
262For all supported boards there are ready-to-use default
263configurations available; just type "make <board_name>_config".
264
265Example: For a TQM823L module type:
266
267	cd u-boot
268	make TQM823L_config
269
270For the Cogent platform, you need to specify the cpu type as well;
271e.g. "make cogent_mpc8xx_config". And also configure the cogent
272directory according to the instructions in cogent/README.
273
274
275Configuration Options:
276----------------------
277
278Configuration depends on the combination of board and CPU type; all
279such information is kept in a configuration file
280"include/configs/<board_name>.h".
281
282Example: For a TQM823L module, all configuration settings are in
283"include/configs/TQM823L.h".
284
285
286Many of the options are named exactly as the corresponding Linux
287kernel configuration options. The intention is to make it easier to
288build a config tool - later.
289
290
291The following options need to be configured:
292
293- CPU Type:	Define exactly one of
294
295		PowerPC based CPUs:
296		-------------------
297		CONFIG_MPC823,	CONFIG_MPC850,	CONFIG_MPC855,	CONFIG_MPC860
298	or	CONFIG_MPC5xx
299	or	CONFIG_MPC824X, CONFIG_MPC8260
300	or	CONFIG_IOP480
301	or	CONFIG_405GP
302	or	CONFIG_440
303	or	CONFIG_MPC74xx
304
305		ARM based CPUs:
306		---------------
307		CONFIG_SA1110
308		CONFIG_ARM7
309		CONFIG_PXA250
310
311
312- Board Type:	Define exactly one of
313
314		PowerPC based boards:
315		---------------------
316
317		CONFIG_ADCIOP,     CONFIG_ICU862      CONFIG_RPXsuper,
318		CONFIG_ADS860,     CONFIG_IP860,      CONFIG_SM850,
319		CONFIG_AMX860,     CONFIG_IPHASE4539, CONFIG_SPD823TS,
320		CONFIG_AR405,      CONFIG_IVML24,     CONFIG_SXNI855T,
321		CONFIG_BAB7xx,     CONFIG_IVML24_128, CONFIG_Sandpoint8240,
322		CONFIG_CANBT,      CONFIG_IVML24_256, CONFIG_Sandpoint8245,
323		CONFIG_CCM,        CONFIG_IVMS8,      CONFIG_TQM823L,
324		CONFIG_CPCI405,    CONFIG_IVMS8_128,  CONFIG_TQM850L,
325		CONFIG_CPCI4052,   CONFIG_IVMS8_256,  CONFIG_TQM855L,
326		CONFIG_CPCIISER4,  CONFIG_LANTEC,     CONFIG_TQM860L,
327		CONFIG_CPU86,      CONFIG_MBX,        CONFIG_TQM8260,
328		CONFIG_CRAYL1,     CONFIG_MBX860T,    CONFIG_TTTech,
329		CONFIG_CU824,      CONFIG_MHPC,       CONFIG_UTX8245,
330		CONFIG_DASA_SIM,   CONFIG_MIP405,     CONFIG_W7OLMC,
331		CONFIG_DU405,      CONFIG_MOUSSE,     CONFIG_W7OLMG,
332		CONFIG_ELPPC,      CONFIG_MPC8260ADS, CONFIG_WALNUT405,
333		CONFIG_ERIC,       CONFIG_MUSENKI,    CONFIG_ZUMA,
334		CONFIG_ESTEEM192E, CONFIG_MVS1,       CONFIG_c2mon,
335		CONFIG_ETX094,     CONFIG_NX823,      CONFIG_cogent_mpc8260,
336		CONFIG_EVB64260,   CONFIG_OCRTC,      CONFIG_cogent_mpc8xx,
337		CONFIG_FADS823,    CONFIG_ORSG,       CONFIG_ep8260,
338		CONFIG_FADS850SAR, CONFIG_OXC,        CONFIG_gw8260,
339		CONFIG_FADS860T,   CONFIG_PCI405,     CONFIG_hermes,
340		CONFIG_FLAGADM,    CONFIG_PCIPPC2,    CONFIG_hymod,
341		CONFIG_FPS850L,    CONFIG_PCIPPC6,    CONFIG_lwmon,
342		CONFIG_GEN860T,    CONFIG_PIP405,     CONFIG_pcu_e,
343		CONFIG_GENIETV,    CONFIG_PM826,      CONFIG_ppmc8260,
344		CONFIG_GTH,        CONFIG_RPXClassic, CONFIG_rsdproto,
345		CONFIG_IAD210,     CONFIG_RPXlite,    CONFIG_sbc8260,
346		CONFIG_EBONY,      CONFIG_sacsng,     CONFIG_FPS860L,
347		CONFIG_V37,        CONFIG_ELPT860,    CONFIG_CMI,
348		CONFIG_NETVIA,     CONFIG_RBC823
349
350		ARM based boards:
351		-----------------
352
353		CONFIG_HHP_CRADLE,  CONFIG_DNP1110,    CONFIG_EP7312,
354		CONFIG_IMPA7,       CONFIG_LART,       CONFIG_LUBBOCK,
355		CONFIG_SHANNON,     CONFIG_SMDK2400,   CONFIG_SMDK2410,
356		CONFIG_TRAB,	    CONFIG_AT91RM9200DK
357
358
359- CPU Module Type: (if CONFIG_COGENT is defined)
360		Define exactly one of
361		CONFIG_CMA286_60_OLD
362--- FIXME --- not tested yet:
363		CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
364		CONFIG_CMA287_23, CONFIG_CMA287_50
365
366- Motherboard Type: (if CONFIG_COGENT is defined)
367		Define exactly one of
368		CONFIG_CMA101, CONFIG_CMA102
369
370- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
371		Define one or more of
372		CONFIG_CMA302
373
374- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
375		Define one or more of
376		CONFIG_LCD_HEARTBEAT	- update a character position on
377					  the lcd display every second with
378					  a "rotator" |\-/|\-/
379
380- MPC824X Family Member (if CONFIG_MPC824X is defined)
381	Define exactly one of
382	CONFIG_MPC8240, CONFIG_MPC8245
383
384- 8xx CPU Options: (if using an 8xx cpu)
385		Define one or more of
386		CONFIG_8xx_GCLK_FREQ	- if get_gclk_freq() can not work e.g.
387					  no 32KHz reference PIT/RTC clock
388
389- Clock Interface:
390		CONFIG_CLOCKS_IN_MHZ
391
392		U-Boot stores all clock information in Hz
393		internally. For binary compatibility with older Linux
394		kernels (which expect the clocks passed in the
395		bd_info data to be in MHz) the environment variable
396		"clocks_in_mhz" can be defined so that U-Boot
397		converts clock data to MHZ before passing it to the
398		Linux kernel.
399
400		When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
401		"clocks_in_mhz=1" is  automatically  included  in  the
402		default environment.
403
404- Console Interface:
405		Depending on board, define exactly one serial port
406		(like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
407		CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
408		console by defining CONFIG_8xx_CONS_NONE
409
410		Note: if CONFIG_8xx_CONS_NONE is defined, the serial
411		port routines must be defined elsewhere
412		(i.e. serial_init(), serial_getc(), ...)
413
414		CONFIG_CFB_CONSOLE
415		Enables console device for a color framebuffer. Needs following
416		defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
417			VIDEO_FB_LITTLE_ENDIAN	graphic memory organisation
418						(default big endian)
419			VIDEO_HW_RECTFILL	graphic chip supports
420						rectangle fill
421						(cf. smiLynxEM)
422			VIDEO_HW_BITBLT		graphic chip supports
423						bit-blit (cf. smiLynxEM)
424			VIDEO_VISIBLE_COLS	visible pixel columns
425						(cols=pitch)
426			VIDEO_VISIBLE_ROWS      visible pixel rows
427			VIDEO_PIXEL_SIZE        bytes per pixel
428			VIDEO_DATA_FORMAT	graphic data format
429						(0-5, cf. cfb_console.c)
430			VIDEO_FB_ADRS           framebuffer address
431			VIDEO_KBD_INIT_FCT	keyboard int fct
432						(i.e. i8042_kbd_init())
433			VIDEO_TSTC_FCT		test char fct
434						(i.e. i8042_tstc)
435			VIDEO_GETC_FCT		get char fct
436						(i.e. i8042_getc)
437			CONFIG_CONSOLE_CURSOR	cursor drawing on/off
438						(requires blink timer
439						cf. i8042.c)
440			CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
441			CONFIG_CONSOLE_TIME	display time/date info in
442						upper right corner
443						(requires CFG_CMD_DATE)
444			CONFIG_VIDEO_LOGO	display Linux logo in
445						upper left corner
446			CONFIG_VIDEO_BMP_LOGO	use bmp_logo.h instead of
447						linux_logo.h for logo.
448						Requires CONFIG_VIDEO_LOGO
449			CONFIG_CONSOLE_EXTRA_INFO
450						addional board info beside
451						the logo
452
453		When CONFIG_CFB_CONSOLE is defined, video console is
454		default i/o. Serial console can be forced with
455		environment 'console=serial'.
456
457- Console Baudrate:
458		CONFIG_BAUDRATE - in bps
459		Select one of the baudrates listed in
460		CFG_BAUDRATE_TABLE, see below.
461
462- Interrupt driven serial port input:
463		CONFIG_SERIAL_SOFTWARE_FIFO
464
465		PPC405GP only.
466		Use an interrupt handler for receiving data on the
467		serial port. It also enables using hardware handshake
468		(RTS/CTS) and UART's built-in FIFO. Set the number of
469		bytes the interrupt driven input buffer should have.
470
471		Set to 0 to disable this feature (this is the default).
472		This will also disable hardware handshake.
473
474- Console UART Number:
475		CONFIG_UART1_CONSOLE
476
477		IBM PPC4xx only.
478		If defined internal UART1 (and not UART0) is used
479		as default U-Boot console.
480
481- Boot Delay:	CONFIG_BOOTDELAY - in seconds
482		Delay before automatically booting the default image;
483		set to -1 to disable autoboot.
484
485		See doc/README.autoboot for these options that
486		work with CONFIG_BOOTDELAY. None are required.
487		CONFIG_BOOT_RETRY_TIME
488		CONFIG_BOOT_RETRY_MIN
489		CONFIG_AUTOBOOT_KEYED
490		CONFIG_AUTOBOOT_PROMPT
491		CONFIG_AUTOBOOT_DELAY_STR
492		CONFIG_AUTOBOOT_STOP_STR
493		CONFIG_AUTOBOOT_DELAY_STR2
494		CONFIG_AUTOBOOT_STOP_STR2
495		CONFIG_ZERO_BOOTDELAY_CHECK
496		CONFIG_RESET_TO_RETRY
497
498- Autoboot Command:
499		CONFIG_BOOTCOMMAND
500		Only needed when CONFIG_BOOTDELAY is enabled;
501		define a command string that is automatically executed
502		when no character is read on the console interface
503		within "Boot Delay" after reset.
504
505		CONFIG_BOOTARGS
506		This can be used to pass arguments to the bootm
507		command. The value of CONFIG_BOOTARGS goes into the
508		environment value "bootargs".
509
510		CONFIG_RAMBOOT and CONFIG_NFSBOOT
511		The value of these goes into the environment as
512		"ramboot" and "nfsboot" respectively, and can be used
513		as a convenience, when switching between booting from
514		ram and nfs.
515
516- Pre-Boot Commands:
517		CONFIG_PREBOOT
518
519		When this option is #defined, the existence of the
520		environment variable "preboot" will be checked
521		immediately before starting the CONFIG_BOOTDELAY
522		countdown and/or running the auto-boot command resp.
523		entering interactive mode.
524
525		This feature is especially useful when "preboot" is
526		automatically generated or modified. For an example
527		see the LWMON board specific code: here "preboot" is
528		modified when the user holds down a certain
529		combination of keys on the (special) keyboard when
530		booting the systems
531
532- Serial Download Echo Mode:
533		CONFIG_LOADS_ECHO
534		If defined to 1, all characters received during a
535		serial download (using the "loads" command) are
536		echoed back. This might be needed by some terminal
537		emulations (like "cu"), but may as well just take
538		time on others. This setting #define's the initial
539		value of the "loads_echo" environment variable.
540
541- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
542		CONFIG_KGDB_BAUDRATE
543		Select one of the baudrates listed in
544		CFG_BAUDRATE_TABLE, see below.
545
546- Monitor Functions:
547		CONFIG_COMMANDS
548		Most monitor functions can be selected (or
549		de-selected) by adjusting the definition of
550		CONFIG_COMMANDS; to select individual functions,
551		#define CONFIG_COMMANDS by "OR"ing any of the
552		following values:
553
554		#define enables commands:
555		-------------------------
556		CFG_CMD_ASKENV	* ask for env variable
557		CFG_CMD_BDI	  bdinfo
558		CFG_CMD_BEDBUG	  Include BedBug Debugger
559		CFG_CMD_BOOTD	  bootd
560		CFG_CMD_CACHE	  icache, dcache
561		CFG_CMD_CONSOLE	  coninfo
562		CFG_CMD_DATE	* support for RTC, date/time...
563		CFG_CMD_DHCP	  DHCP support
564		CFG_CMD_ECHO	* echo arguments
565		CFG_CMD_EEPROM	* EEPROM read/write support
566		CFG_CMD_ELF	  bootelf, bootvx
567		CFG_CMD_ENV	  saveenv
568		CFG_CMD_FDC	* Floppy Disk Support
569		CFG_CMD_FAT	  FAT partition support
570		CFG_CMD_FDOS	* Dos diskette Support
571		CFG_CMD_FLASH	  flinfo, erase, protect
572		CFG_CMD_FPGA	  FPGA device initialization support
573		CFG_CMD_I2C	* I2C serial bus support
574		CFG_CMD_IDE	* IDE harddisk support
575		CFG_CMD_IMI	  iminfo
576		CFG_CMD_IMMAP	* IMMR dump support
577		CFG_CMD_IRQ	* irqinfo
578		CFG_CMD_KGDB	* kgdb
579		CFG_CMD_LOADB	  loadb
580		CFG_CMD_LOADS	  loads
581		CFG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base,
582				  loop, mtest
583		CFG_CMD_MMC	  MMC memory mapped support
584		CFG_CMD_MII	  MII utility commands
585		CFG_CMD_NET	  bootp, tftpboot, rarpboot
586		CFG_CMD_PCI	* pciinfo
587		CFG_CMD_PCMCIA	* PCMCIA support
588		CFG_CMD_REGINFO * Register dump
589		CFG_CMD_RUN	  run command in env variable
590		CFG_CMD_SCSI	* SCSI Support
591		CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
592		CFG_CMD_SPI	* SPI serial bus support
593		CFG_CMD_USB	* USB support
594		CFG_CMD_BSP	* Board SPecific functions
595		-----------------------------------------------
596		CFG_CMD_ALL	all
597
598		CFG_CMD_DFL	Default configuration; at the moment
599				this is includes all commands, except
600				the ones marked with "*" in the list
601				above.
602
603		If you don't define CONFIG_COMMANDS it defaults to
604		CFG_CMD_DFL in include/cmd_confdefs.h. A board can
605		override the default settings in the respective
606		include file.
607
608		EXAMPLE: If you want all functions except of network
609		support you can write:
610
611		#define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
612
613
614	Note:	Don't enable the "icache" and "dcache" commands
615		(configuration option CFG_CMD_CACHE) unless you know
616		what you (and your U-Boot users) are doing. Data
617		cache cannot be enabled on systems like the 8xx or
618		8260 (where accesses to the IMMR region must be
619		uncached), and it cannot be disabled on all other
620		systems where we (mis-) use the data cache to hold an
621		initial stack and some data.
622
623
624		XXX - this list needs to get updated!
625
626- Watchdog:
627		CONFIG_WATCHDOG
628		If this variable is defined, it enables watchdog
629		support. There must support in the platform specific
630		code for a watchdog. For the 8xx and 8260 CPUs, the
631		SIU Watchdog feature is enabled in the SYPCR
632		register.
633
634- U-Boot Version:
635		CONFIG_VERSION_VARIABLE
636		If this variable is defined, an environment variable
637		named "ver" is created by U-Boot showing the U-Boot
638		version as printed by the "version" command.
639		This variable is readonly.
640
641- Real-Time Clock:
642
643		When CFG_CMD_DATE is selected, the type of the RTC
644		has to be selected, too. Define exactly one of the
645		following options:
646
647		CONFIG_RTC_MPC8xx	- use internal RTC of MPC8xx
648		CONFIG_RTC_PCF8563	- use Philips PCF8563 RTC
649		CONFIG_RTC_MC146818	- use MC146818 RTC
650		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC
651		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC
652		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC
653		CONFIG_RTC_DS164x	- use Dallas DS164x RTC
654
655- Timestamp Support:
656
657		When CONFIG_TIMESTAMP is selected, the timestamp
658		(date and time) of an image is printed by image
659		commands like bootm or iminfo. This option is
660		automatically enabled when you select CFG_CMD_DATE .
661
662- Partition Support:
663		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
664		and/or CONFIG_ISO_PARTITION
665
666		If IDE or SCSI support	is  enabled  (CFG_CMD_IDE  or
667		CFG_CMD_SCSI) you must configure support for at least
668		one partition type as well.
669
670- IDE Reset method:
671		CONFIG_IDE_RESET_ROUTINE
672
673		Set this to define that instead of a reset Pin, the
674		routine ide_set_reset(int idereset) will be used.
675
676- ATAPI Support:
677		CONFIG_ATAPI
678
679		Set this to enable ATAPI support.
680
681- SCSI Support:
682		At the moment only there is only support for the
683		SYM53C8XX SCSI controller; define
684		CONFIG_SCSI_SYM53C8XX to enable it.
685
686		CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
687		CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
688		CFG_SCSI_MAX_LUN] can be adjusted to define the
689		maximum numbers of LUNs, SCSI ID's and target
690		devices.
691		CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
692
693- NETWORK Support (PCI):
694		CONFIG_E1000
695		Support for Intel 8254x gigabit chips.
696
697		CONFIG_EEPRO100
698		Support for Intel 82557/82559/82559ER chips.
699		Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
700		write routine for first time initialisation.
701
702		CONFIG_TULIP
703		Support for Digital 2114x chips.
704		Optional CONFIG_TULIP_SELECT_MEDIA for board specific
705		modem chip initialisation (KS8761/QS6611).
706
707		CONFIG_NATSEMI
708		Support for National dp83815 chips.
709
710		CONFIG_NS8382X
711		Support for National dp8382[01] gigabit chips.
712
713- NETWORK Support (other):
714
715		CONFIG_DRIVER_LAN91C96
716		Support for SMSC's LAN91C96 chips.
717
718			CONFIG_LAN91C96_BASE
719			Define this to hold the physical address
720			of the LAN91C96's I/O space
721
722			CONFIG_LAN91C96_USE_32_BIT
723			Define this to enable 32 bit addressing
724
725- USB Support:
726		At the moment only the UHCI host controller is
727		supported (PIP405, MIP405); define
728		CONFIG_USB_UHCI to enable it.
729		define CONFIG_USB_KEYBOARD to enable the USB Keyboard
730		end define CONFIG_USB_STORAGE to enable the USB
731		storage devices.
732		Note:
733		Supported are USB Keyboards and USB Floppy drives
734		(TEAC FD-05PUB).
735
736- MMC Support:
737  		The MMC controller on the Intel PXA is supported. To
738		enable this define CONFIG_MMC. The MMC can be
739		accessed from the boot prompt by mapping the device
740		to physical memory similar to flash. Command line is
741		enabled with CFG_CMD_MMC. The MMC driver also works with
742		the FAT fs. This is enabled with CFG_CMD_FAT.
743
744- Keyboard Support:
745		CONFIG_ISA_KEYBOARD
746
747		Define this to enable standard (PC-Style) keyboard
748		support
749
750		CONFIG_I8042_KBD
751		Standard PC keyboard driver with US (is default) and
752		GERMAN key layout (switch via environment 'keymap=de') support.
753		Export function i8042_kbd_init, i8042_tstc and i8042_getc
754		for cfb_console. Supports cursor blinking.
755
756- Video support:
757		CONFIG_VIDEO
758
759		Define this to enable video support (for output to
760		video).
761
762		CONFIG_VIDEO_CT69000
763
764		Enable Chips & Technologies 69000 Video chip
765
766		CONFIG_VIDEO_SMI_LYNXEM
767		Enable Silicon Motion SMI 712/710/810 Video chip
768		Videomode are selected via environment 'videomode' with
769		standard LiLo mode numbers.
770		Following modes are supported  (* is default):
771
772			    800x600  1024x768  1280x1024
773	      256  (8bit)     303*      305       307
774	    65536 (16bit)     314       317       31a
775	16,7 Mill (24bit)     315       318       31b
776		(i.e. setenv videomode 317; saveenv; reset;)
777
778		CONFIG_VIDEO_SED13806
779		Enable Epson SED13806 driver. This driver supports 8bpp
780		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
781		or CONFIG_VIDEO_SED13806_16BPP
782
783- Keyboard Support:
784                CONFIG_KEYBOARD
785
786                Define this to enable a custom keyboard support.
787                This simply calls drv_keyboard_init() which must be
788                defined in your board-specific files.
789                The only board using this so far is RBC823.
790
791- LCD Support:	CONFIG_LCD
792
793		Define this to enable LCD support (for output to LCD
794		display); also select one of the supported displays
795		by defining one of these:
796
797		CONFIG_NEC_NL6648AC33:
798
799			NEC NL6648AC33-18. Active, color, single scan.
800
801		CONFIG_NEC_NL6648BC20
802
803			NEC NL6648BC20-08. 6.5", 640x480.
804			Active, color, single scan.
805
806		CONFIG_SHARP_16x9
807
808			Sharp 320x240. Active, color, single scan.
809			It isn't 16x9, and I am not sure what it is.
810
811		CONFIG_SHARP_LQ64D341
812
813			Sharp LQ64D341 display, 640x480.
814			Active, color, single scan.
815
816		CONFIG_HLD1045
817
818			HLD1045 display, 640x480.
819			Active, color, single scan.
820
821		CONFIG_OPTREX_BW
822
823			Optrex	 CBL50840-2 NF-FW 99 22 M5
824			or
825			Hitachi	 LMG6912RPFC-00T
826			or
827			Hitachi	 SP14Q002
828
829			320x240. Black & white.
830
831		Normally display is black on white background; define
832		CFG_WHITE_ON_BLACK to get it inverted.
833
834- Spash Screen Support: CONFIG_SPLASH_SCREEN
835
836                If this option is set, the environment is checked for
837                a variable "splashimage". If found, the usual display
838                of logo, copyright and system information on the LCD
839                is supressed and the BMP image at the address
840                specified in "splashimage" is loaded instead. The
841                console is redirected to the "nulldev", too. This
842                allows for a "silent" boot where a splash screen is
843                loaded very quickly after power-on.
844
845
846- Ethernet address:
847		CONFIG_ETHADDR
848		CONFIG_ETH2ADDR
849		CONFIG_ETH3ADDR
850
851		Define a default value for ethernet address to use
852		for the respective ethernet interface, in case this
853		is not determined automatically.
854
855- IP address:
856		CONFIG_IPADDR
857
858		Define a default value for the IP address to use for
859		the default ethernet interface, in case this is not
860		determined through e.g. bootp.
861
862- Server IP address:
863		CONFIG_SERVERIP
864
865		Defines a default value for theIP address of a TFTP
866		server to contact when using the "tftboot" command.
867
868- BOOTP Recovery Mode:
869		CONFIG_BOOTP_RANDOM_DELAY
870
871		If you have many targets in a network that try to
872		boot using BOOTP, you may want to avoid that all
873		systems send out BOOTP requests at precisely the same
874		moment (which would happen for instance at recovery
875		from a power failure, when all systems will try to
876		boot, thus flooding the BOOTP server. Defining
877		CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
878		inserted before sending out BOOTP requests. The
879		following delays are insterted then:
880
881		1st BOOTP request:	delay 0 ... 1 sec
882		2nd BOOTP request:	delay 0 ... 2 sec
883		3rd BOOTP request:	delay 0 ... 4 sec
884		4th and following
885		BOOTP requests:		delay 0 ... 8 sec
886
887- Status LED:	CONFIG_STATUS_LED
888
889		Several configurations allow to display the current
890		status using a LED. For instance, the LED will blink
891		fast while running U-Boot code, stop blinking as
892		soon as a reply to a BOOTP request was received, and
893		start blinking slow once the Linux kernel is running
894		(supported by a status LED driver in the Linux
895		kernel). Defining CONFIG_STATUS_LED enables this
896		feature in U-Boot.
897
898- CAN Support:	CONFIG_CAN_DRIVER
899
900		Defining CONFIG_CAN_DRIVER enables CAN driver support
901		on those systems that support this (optional)
902		feature, like the TQM8xxL modules.
903
904- I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C
905
906		Enables I2C serial bus commands.  If this is selected,
907		either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
908		to include the appropriate I2C driver.
909
910		See also: common/cmd_i2c.c for a description of the
911		command line interface.
912
913
914		CONFIG_HARD_I2C
915
916		Selects the CPM hardware driver for I2C.
917
918		CONFIG_SOFT_I2C
919
920		Use software (aka bit-banging) driver instead of CPM
921		or similar hardware support for I2C.  This is configured
922		via the following defines.
923
924		I2C_INIT
925
926		(Optional). Any commands necessary to enable I2C
927		controller or configure ports.
928
929		I2C_PORT
930
931		(Only for MPC8260 CPU). The I/O port to use (the code
932		assumes both bits are on the same port). Valid values
933		are 0..3 for ports A..D.
934
935		I2C_ACTIVE
936
937		The code necessary to make the I2C data line active
938		(driven).  If the data line is open collector, this
939		define can be null.
940
941		I2C_TRISTATE
942
943		The code necessary to make the I2C data line tri-stated
944		(inactive).  If the data line is open collector, this
945		define can be null.
946
947		I2C_READ
948
949		Code that returns TRUE if the I2C data line is high,
950		FALSE if it is low.
951
952		I2C_SDA(bit)
953
954		If <bit> is TRUE, sets the I2C data line high. If it
955		is FALSE, it clears it (low).
956
957		I2C_SCL(bit)
958
959		If <bit> is TRUE, sets the I2C clock line high. If it
960		is FALSE, it clears it (low).
961
962		I2C_DELAY
963
964		This delay is invoked four times per clock cycle so this
965		controls the rate of data transfer.  The data rate thus
966		is 1 / (I2C_DELAY * 4).
967
968		CFG_I2C_INIT_BOARD
969
970                When a board is reset during an i2c bus transfer
971                chips might think that the current transfer is still
972                in progress. On some boards it is possible to access
973                the i2c SCLK line directly, either by using the
974                processor pin as a GPIO or by having a second pin
975                connected to the bus. If this option is defined a
976                custom i2c_init_board() routine in boards/xxx/board.c
977                is run early in the boot sequence.
978
979- SPI Support:	CONFIG_SPI
980
981		Enables SPI driver (so far only tested with
982		SPI EEPROM, also an instance works with Crystal A/D and
983		D/As on the SACSng board)
984
985		CONFIG_SPI_X
986
987		Enables extended (16-bit) SPI EEPROM addressing.
988		(symmetrical to CONFIG_I2C_X)
989
990		CONFIG_SOFT_SPI
991
992		Enables a software (bit-bang) SPI driver rather than
993		using hardware support. This is a general purpose
994		driver that only requires three general I/O port pins
995		(two outputs, one input) to function. If this is
996		defined, the board configuration must define several
997		SPI configuration items (port pins to use, etc). For
998		an example, see include/configs/sacsng.h.
999
1000- FPGA Support: CONFIG_FPGA_COUNT
1001
1002		Specify the number of FPGA devices to support.
1003
1004		CONFIG_FPGA
1005
1006		Used to specify the types of FPGA devices. For
1007		example,
1008 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
1009
1010 		CFG_FPGA_PROG_FEEDBACK
1011
1012		Enable printing of hash marks during FPGA
1013		configuration.
1014
1015		CFG_FPGA_CHECK_BUSY
1016
1017		Enable checks on FPGA configuration interface busy
1018		status by the configuration function. This option
1019		will require a board or device specific function to
1020		be written.
1021
1022		CONFIG_FPGA_DELAY
1023
1024		If defined, a function that provides delays in the
1025		FPGA configuration driver.
1026
1027		CFG_FPGA_CHECK_CTRLC
1028
1029		Allow Control-C to interrupt FPGA configuration
1030
1031		CFG_FPGA_CHECK_ERROR
1032
1033		Check for configuration errors during FPGA bitfile
1034		loading. For example, abort during Virtex II
1035		configuration if the INIT_B line goes low (which
1036		indicated a CRC error).
1037
1038		CFG_FPGA_WAIT_INIT
1039
1040		Maximum time to wait for the INIT_B line to deassert
1041		after PROB_B has been deasserted during a Virtex II
1042		FPGA configuration sequence. The default time is 500 mS.
1043
1044		CFG_FPGA_WAIT_BUSY
1045
1046		Maximum time to wait for BUSY to deassert during
1047		Virtex II FPGA configuration. The default is 5 mS.
1048
1049		CFG_FPGA_WAIT_CONFIG
1050
1051		Time to wait after FPGA configuration. The default is
1052		200 mS.
1053
1054- FPGA Support:	CONFIG_FPGA_COUNT
1055
1056 		Specify the number of FPGA devices to support.
1057
1058 		CONFIG_FPGA
1059
1060 		Used to specify the types of FPGA devices.  For example,
1061 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
1062
1063 		CFG_FPGA_PROG_FEEDBACK
1064
1065 		Enable printing of hash marks during FPGA configuration.
1066
1067		CFG_FPGA_CHECK_BUSY
1068
1069		Enable checks on FPGA configuration interface busy
1070		status by the configuration function. This option
1071		will require a board or device specific function to
1072		be written.
1073
1074		CONFIG_FPGA_DELAY
1075
1076		If defined, a function that provides delays in the FPGA
1077		configuration driver.
1078
1079		CFG_FPGA_CHECK_CTRLC
1080		Allow Control-C to interrupt FPGA configuration
1081
1082		CFG_FPGA_CHECK_ERROR
1083
1084		Check for configuration errors during FPGA bitfile
1085		loading. For example, abort during Virtex II
1086		configuration if the INIT_B line goes low (which
1087		indicated a CRC error).
1088
1089		CFG_FPGA_WAIT_INIT
1090
1091		Maximum time to wait for the INIT_B line to deassert
1092		after PROB_B has been deasserted during a Virtex II
1093		FPGA configuration sequence. The default time is 500
1094		mS.
1095
1096		CFG_FPGA_WAIT_BUSY
1097
1098		Maximum time to wait for BUSY to deassert during
1099		Virtex II FPGA configuration. The default is 5 mS.
1100
1101		CFG_FPGA_WAIT_CONFIG
1102
1103		Time to wait after FPGA configuration. The default is
1104		200 mS.
1105
1106- Configuration Management:
1107		CONFIG_IDENT_STRING
1108
1109		If defined, this string will be added to the U-Boot
1110		version information (U_BOOT_VERSION)
1111
1112- Vendor Parameter Protection:
1113
1114		U-Boot considers the values of the environment
1115		variables "serial#" (Board Serial Number) and
1116		"ethaddr" (Ethernet Address) to bb parameters that
1117		are set once by the board vendor / manufacturer, and
1118		protects these variables from casual modification by
1119		the user. Once set, these variables are read-only,
1120		and write or delete attempts are rejected. You can
1121		change this behviour:
1122
1123		If CONFIG_ENV_OVERWRITE is #defined in your config
1124		file, the write protection for vendor parameters is
1125		completely disabled. Anybody can change or delete
1126		these parameters.
1127
1128		Alternatively, if you #define _both_ CONFIG_ETHADDR
1129		_and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1130		ethernet address is installed in the environment,
1131		which can be changed exactly ONCE by the user. [The
1132		serial# is unaffected by this, i. e. it remains
1133		read-only.]
1134
1135- Protected RAM:
1136		CONFIG_PRAM
1137
1138		Define this variable to enable the reservation of
1139		"protected RAM", i. e. RAM which is not overwritten
1140		by U-Boot. Define CONFIG_PRAM to hold the number of
1141		kB you want to reserve for pRAM. You can overwrite
1142		this default value by defining an environment
1143		variable "pram" to the number of kB you want to
1144		reserve. Note that the board info structure will
1145		still show the full amount of RAM. If pRAM is
1146		reserved, a new environment variable "mem" will
1147		automatically be defined to hold the amount of
1148		remaining RAM in a form that can be passed as boot
1149		argument to Linux, for instance like that:
1150
1151			setenv bootargs ... mem=\$(mem)
1152			saveenv
1153
1154		This way you can tell Linux not to use this memory,
1155		either, which results in a memory region that will
1156		not be affected by reboots.
1157
1158		*WARNING* If your board configuration uses automatic
1159		detection of the RAM size, you must make sure that
1160		this memory test is non-destructive. So far, the
1161		following board configurations are known to be
1162		"pRAM-clean":
1163
1164			ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1165			HERMES, IP860, RPXlite, LWMON, LANTEC,
1166			PCU_E, FLAGADM, TQM8260
1167
1168- Error Recovery:
1169		CONFIG_PANIC_HANG
1170
1171		Define this variable to stop the system in case of a
1172		fatal error, so that you have to reset it manually.
1173		This is probably NOT a good idea for an embedded
1174		system where you want to system to reboot
1175		automatically as fast as possible, but it may be
1176		useful during development since you can try to debug
1177		the conditions that lead to the situation.
1178
1179		CONFIG_NET_RETRY_COUNT
1180
1181		This variable defines the number of retries for
1182		network operations like ARP, RARP, TFTP, or BOOTP
1183		before giving up the operation. If not defined, a
1184		default value of 5 is used.
1185
1186- Command Interpreter:
1187		CFG_HUSH_PARSER
1188
1189		Define this variable to enable the "hush" shell (from
1190		Busybox) as command line interpreter, thus enabling
1191		powerful command line syntax like
1192		if...then...else...fi conditionals or `&&' and '||'
1193		constructs ("shell scripts").
1194
1195		If undefined, you get the old, much simpler behaviour
1196		with a somewhat smaller memory footprint.
1197
1198
1199		CFG_PROMPT_HUSH_PS2
1200
1201		This defines the secondary prompt string, which is
1202		printed when the command interpreter needs more input
1203		to complete a command. Usually "> ".
1204
1205	Note:
1206
1207                In the current implementation, the local variables
1208                space and global environment variables space are
1209                separated. Local variables are those you define by
1210                simply typing `name=value'. To access a local
1211                variable later on, you have write `$name' or
1212                `${name}'; to execute the contents of a variable
1213                directly type `$name' at the command prompt.
1214
1215		Global environment variables are those you use
1216		setenv/printenv to work with. To run a command stored
1217		in such a variable, you need to use the run command,
1218		and you must not use the '$' sign to access them.
1219
1220		To store commands and special characters in a
1221		variable, please use double quotation marks
1222		surrounding the whole text of the variable, instead
1223		of the backslashes before semicolons and special
1224		symbols.
1225
1226- Default Environment
1227		CONFIG_EXTRA_ENV_SETTINGS
1228
1229		Define this to contain any number of null terminated
1230		strings (variable = value pairs) that will be part of
1231		the default enviroment compiled into the boot image.
1232
1233		For example, place something like this in your
1234		board's config file:
1235
1236		#define CONFIG_EXTRA_ENV_SETTINGS \
1237			"myvar1=value1\0" \
1238			"myvar2=value2\0"
1239
1240		Warning: This method is based on knowledge about the
1241		internal format how the environment is stored by the
1242		U-Boot code. This is NOT an official, exported
1243		interface! Although it is unlikely that this format
1244		will change soon, but there is no guarantee either.
1245		You better know what you are doing here.
1246
1247		Note: overly (ab)use of the default environment is
1248		discouraged. Make sure to check other ways to preset
1249		the environment like the autoscript function or the
1250		boot command first.
1251
1252- DataFlash Support
1253		CONFIG_HAS_DATAFLASH
1254
1255                Defining this option enables DataFlash features and
1256                allows to read/write in Dataflash via the standard
1257                commands cp, md...
1258
1259- Show boot progress
1260		CONFIG_SHOW_BOOT_PROGRESS
1261
1262		Defining this option allows to add some board-
1263		specific code (calling a user-provided function
1264		"show_boot_progress(int)") that enables you to show
1265		the system's boot progress on some display (for
1266		example, some LED's) on your board. At the moment,
1267		the following checkpoints are implemented:
1268
1269  Arg	Where			When
1270    1	common/cmd_bootm.c	before attempting to boot an image
1271   -1	common/cmd_bootm.c	Image header has bad     magic number
1272    2	common/cmd_bootm.c	Image header has correct magic number
1273   -2	common/cmd_bootm.c	Image header has bad     checksum
1274    3	common/cmd_bootm.c	Image header has correct checksum
1275   -3	common/cmd_bootm.c	Image data   has bad     checksum
1276    4	common/cmd_bootm.c	Image data   has correct checksum
1277   -4	common/cmd_bootm.c	Image is for unsupported architecture
1278    5	common/cmd_bootm.c	Architecture check OK
1279   -5	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1280    6	common/cmd_bootm.c	Image Type check OK
1281   -6	common/cmd_bootm.c	gunzip uncompression error
1282   -7	common/cmd_bootm.c	Unimplemented compression type
1283    7	common/cmd_bootm.c	Uncompression OK
1284   -8	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1285    8	common/cmd_bootm.c	Image Type check OK
1286   -9	common/cmd_bootm.c	Unsupported OS (not Linux, BSD, VxWorks, QNX)
1287    9	common/cmd_bootm.c	Start initial ramdisk verification
1288  -10	common/cmd_bootm.c	Ramdisk header has bad     magic number
1289  -11	common/cmd_bootm.c	Ramdisk header has bad     checksum
1290   10	common/cmd_bootm.c	Ramdisk header is OK
1291  -12	common/cmd_bootm.c	Ramdisk data   has bad     checksum
1292   11	common/cmd_bootm.c	Ramdisk data   has correct checksum
1293   12	common/cmd_bootm.c	Ramdisk verification complete, start loading
1294  -13	common/cmd_bootm.c	Wrong Image Type (not PPC Linux Ramdisk)
1295   13	common/cmd_bootm.c	Start multifile image verification
1296   14	common/cmd_bootm.c	No initial ramdisk, no multifile, continue.
1297   15	common/cmd_bootm.c	All preparation done, transferring control to OS
1298
1299   -1	common/cmd_doc.c	Bad usage of "doc" command
1300   -1	common/cmd_doc.c	No boot device
1301   -1	common/cmd_doc.c	Unknown Chip ID on boot device
1302   -1	common/cmd_doc.c	Read Error on boot device
1303   -1	common/cmd_doc.c	Image header has bad magic number
1304
1305   -1	common/cmd_ide.c	Bad usage of "ide" command
1306   -1	common/cmd_ide.c	No boot device
1307   -1	common/cmd_ide.c	Unknown boot device
1308   -1	common/cmd_ide.c	Unknown partition table
1309   -1	common/cmd_ide.c	Invalid partition type
1310   -1	common/cmd_ide.c	Read Error on boot device
1311   -1	common/cmd_ide.c	Image header has bad magic number
1312
1313   -1	common/cmd_nvedit.c	Environment not changable, but has bad CRC
1314
1315
1316Modem Support:
1317--------------
1318
1319[so far only for SMDK2400 and TRAB boards]
1320
1321- Modem support endable:
1322		CONFIG_MODEM_SUPPORT
1323
1324- RTS/CTS Flow control enable:
1325		CONFIG_HWFLOW
1326
1327- Modem debug support:
1328		CONFIG_MODEM_SUPPORT_DEBUG
1329
1330		Enables debugging stuff (char screen[1024], dbg())
1331		for modem support. Useful only with BDI2000.
1332
1333- General:
1334
1335		In the target system modem support is enabled when a
1336		specific key (key combination) is pressed during
1337		power-on. Otherwise U-Boot will boot normally
1338		(autoboot). The key_pressed() fuction is called from
1339		board_init(). Currently key_pressed() is a dummy
1340		function, returning 1 and thus enabling modem
1341		initialization.
1342
1343		If there are no modem init strings in the
1344		environment, U-Boot proceed to autoboot; the
1345		previous output (banner, info printfs) will be
1346		supressed, though.
1347
1348		See also: doc/README.Modem
1349
1350
1351
1352
1353Configuration Settings:
1354-----------------------
1355
1356- CFG_LONGHELP: Defined when you want long help messages included;
1357		undefine this when you're short of memory.
1358
1359- CFG_PROMPT:	This is what U-Boot prints on the console to
1360		prompt for user input.
1361
1362- CFG_CBSIZE:	Buffer size for input from the Console
1363
1364- CFG_PBSIZE:	Buffer size for Console output
1365
1366- CFG_MAXARGS:	max. Number of arguments accepted for monitor commands
1367
1368- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1369		the application (usually a Linux kernel) when it is
1370		booted
1371
1372- CFG_BAUDRATE_TABLE:
1373		List of legal baudrate settings for this board.
1374
1375- CFG_CONSOLE_INFO_QUIET
1376 		Suppress display of console information at boot.
1377
1378- CFG_CONSOLE_IS_IN_ENV
1379 		If the board specific function
1380 			extern int overwrite_console (void);
1381 		returns 1, the stdin, stderr and stdout are switched to the
1382		serial port, else the settings in the environment are used.
1383
1384- CFG_CONSOLE_OVERWRITE_ROUTINE
1385 		Enable the call to overwrite_console().
1386
1387- CFG_CONSOLE_ENV_OVERWRITE
1388		Enable overwrite of previous console environment settings.
1389
1390- CFG_MEMTEST_START, CFG_MEMTEST_END:
1391		Begin and End addresses of the area used by the
1392		simple memory test.
1393
1394- CFG_ALT_MEMTEST:
1395 		Enable an alternate, more extensive memory test.
1396
1397- CFG_TFTP_LOADADDR:
1398		Default load address for network file downloads
1399
1400- CFG_LOADS_BAUD_CHANGE:
1401		Enable temporary baudrate change while serial download
1402
1403- CFG_SDRAM_BASE:
1404		Physical start address of SDRAM. _Must_ be 0 here.
1405
1406- CFG_MBIO_BASE:
1407		Physical start address of Motherboard I/O (if using a
1408		Cogent motherboard)
1409
1410- CFG_FLASH_BASE:
1411		Physical start address of Flash memory.
1412
1413- CFG_MONITOR_BASE:
1414		Physical start address of boot monitor code (set by
1415		make config files to be same as the text base address
1416		(TEXT_BASE) used when linking) - same as
1417		CFG_FLASH_BASE when booting from flash.
1418
1419- CFG_MONITOR_LEN:
1420                Size of memory reserved for monitor code, used to
1421                determine _at_compile_time_ (!) if the environment is
1422                embedded within the U-Boot image, or in a separate
1423                flash sector.
1424
1425- CFG_MALLOC_LEN:
1426		Size of DRAM reserved for malloc() use.
1427
1428- CFG_BOOTMAPSZ:
1429		Maximum size of memory mapped by the startup code of
1430		the Linux kernel; all data that must be processed by
1431		the Linux kernel (bd_info, boot arguments, eventually
1432		initrd image) must be put below this limit.
1433
1434- CFG_MAX_FLASH_BANKS:
1435		Max number of Flash memory banks
1436
1437- CFG_MAX_FLASH_SECT:
1438		Max number of sectors on a Flash chip
1439
1440- CFG_FLASH_ERASE_TOUT:
1441		Timeout for Flash erase operations (in ms)
1442
1443- CFG_FLASH_WRITE_TOUT:
1444		Timeout for Flash write operations (in ms)
1445
1446- CFG_DIRECT_FLASH_TFTP:
1447
1448		Enable TFTP transfers directly to flash memory;
1449		without this option such a download has to be
1450		performed in two steps: (1) download to RAM, and (2)
1451		copy from RAM to flash.
1452
1453		The two-step approach is usually more reliable, since
1454		you can check if the download worked before you erase
1455		the flash, but in some situations (when sytem RAM is
1456		too limited to allow for a tempory copy of the
1457		downloaded image) this option may be very useful.
1458
1459- CFG_FLASH_CFI:
1460		Define if the flash driver uses extra elements in the
1461		common flash structure for storing flash geometry
1462
1463- CFG_RX_ETH_BUFFER:
1464		Defines the number of ethernet receive buffers. On some
1465		ethernet controllers it is recommended to set this value
1466		to 8 or even higher (EEPRO100 or 405 EMAC), since all
1467		buffers can be full shortly after enabling the interface
1468		on high ethernet traffic.
1469		Defaults to 4 if not defined.
1470
1471The following definitions that deal with the placement and management
1472of environment data (variable area); in general, we support the
1473following configurations:
1474
1475- CFG_ENV_IS_IN_FLASH:
1476
1477	Define this if the environment is in flash memory.
1478
1479	a) The environment occupies one whole flash sector, which is
1480	   "embedded" in the text segment with the U-Boot code. This
1481	   happens usually with "bottom boot sector" or "top boot
1482	   sector" type flash chips, which have several smaller
1483	   sectors at the start or the end. For instance, such a
1484	   layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1485	   such a case you would place the environment in one of the
1486	   4 kB sectors - with U-Boot code before and after it. With
1487	   "top boot sector" type flash chips, you would put the
1488	   environment in one of the last sectors, leaving a gap
1489	   between U-Boot and the environment.
1490
1491	- CFG_ENV_OFFSET:
1492
1493	   Offset of environment data (variable area) to the
1494	   beginning of flash memory; for instance, with bottom boot
1495	   type flash chips the second sector can be used: the offset
1496	   for this sector is given here.
1497
1498	   CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1499
1500	- CFG_ENV_ADDR:
1501
1502	   This is just another way to specify the start address of
1503	   the flash sector containing the environment (instead of
1504	   CFG_ENV_OFFSET).
1505
1506	- CFG_ENV_SECT_SIZE:
1507
1508	   Size of the sector containing the environment.
1509
1510
1511	b) Sometimes flash chips have few, equal sized, BIG sectors.
1512	   In such a case you don't want to spend a whole sector for
1513	   the environment.
1514
1515	- CFG_ENV_SIZE:
1516
1517	   If you use this in combination with CFG_ENV_IS_IN_FLASH
1518	   and CFG_ENV_SECT_SIZE, you can specify to use only a part
1519	   of this flash sector for the environment. This saves
1520	   memory for the RAM copy of the environment.
1521
1522	   It may also save flash memory if you decide to use this
1523	   when your environment is "embedded" within U-Boot code,
1524	   since then the remainder of the flash sector could be used
1525	   for U-Boot code. It should be pointed out that this is
1526	   STRONGLY DISCOURAGED from a robustness point of view:
1527	   updating the environment in flash makes it always
1528	   necessary to erase the WHOLE sector. If something goes
1529	   wrong before the contents has been restored from a copy in
1530	   RAM, your target system will be dead.
1531
1532	- CFG_ENV_ADDR_REDUND
1533	  CFG_ENV_SIZE_REDUND
1534
1535	   These settings describe a second storage area used to hold
1536	   a redundand copy of the environment data, so that there is
1537	   a valid backup copy in case there is a power failure during
1538	   a "saveenv" operation.
1539
1540BE CAREFUL! Any changes to the flash layout, and some changes to the
1541source code will make it necessary to adapt <board>/u-boot.lds*
1542accordingly!
1543
1544
1545- CFG_ENV_IS_IN_NVRAM:
1546
1547	Define this if you have some non-volatile memory device
1548	(NVRAM, battery buffered SRAM) which you want to use for the
1549	environment.
1550
1551	- CFG_ENV_ADDR:
1552	- CFG_ENV_SIZE:
1553
1554	  These two #defines are used to determin the memory area you
1555	  want to use for environment. It is assumed that this memory
1556	  can just be read and written to, without any special
1557	  provision.
1558
1559BE CAREFUL! The first access to the environment happens quite early
1560in U-Boot initalization (when we try to get the setting of for the
1561console baudrate). You *MUST* have mappend your NVRAM area then, or
1562U-Boot will hang.
1563
1564Please note that even with NVRAM we still use a copy of the
1565environment in RAM: we could work on NVRAM directly, but we want to
1566keep settings there always unmodified except somebody uses "saveenv"
1567to save the current settings.
1568
1569
1570- CFG_ENV_IS_IN_EEPROM:
1571
1572	Use this if you have an EEPROM or similar serial access
1573	device and a driver for it.
1574
1575	- CFG_ENV_OFFSET:
1576	- CFG_ENV_SIZE:
1577
1578	  These two #defines specify the offset and size of the
1579	  environment area within the total memory of your EEPROM.
1580
1581	- CFG_I2C_EEPROM_ADDR:
1582	  If defined, specified the chip address of the EEPROM device.
1583	  The default address is zero.
1584
1585	- CFG_EEPROM_PAGE_WRITE_BITS:
1586	  If defined, the number of bits used to address bytes in a
1587	  single page in the EEPROM device.  A 64 byte page, for example
1588	  would require six bits.
1589
1590	- CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1591	  If defined, the number of milliseconds to delay between
1592	  page writes.  The default is zero milliseconds.
1593
1594	- CFG_I2C_EEPROM_ADDR_LEN:
1595	  The length in bytes of the EEPROM memory array address.  Note
1596	  that this is NOT the chip address length!
1597
1598	- CFG_EEPROM_SIZE:
1599	  The size in bytes of the EEPROM device.
1600
1601
1602- CFG_SPI_INIT_OFFSET
1603
1604	Defines offset to the initial SPI buffer area in DPRAM. The
1605	area is used at an early stage (ROM part) if the environment
1606	is configured to reside in the SPI EEPROM: We need a 520 byte
1607	scratch DPRAM area. It is used between the two initialization
1608	calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1609	to be a good choice since it makes it far enough from the
1610	start of the data area as well as from the stack pointer.
1611
1612Please note that the environment is read-only as long as the monitor
1613has been relocated to RAM and a RAM copy of the environment has been
1614created; also, when using EEPROM you will have to use getenv_r()
1615until then to read environment variables.
1616
1617The environment is protected by a CRC32 checksum. Before the monitor
1618is relocated into RAM, as a result of a bad CRC you will be working
1619with the compiled-in default environment - *silently*!!! [This is
1620necessary, because the first environment variable we need is the
1621"baudrate" setting for the console - if we have a bad CRC, we don't
1622have any device yet where we could complain.]
1623
1624Note: once the monitor has been relocated, then it will complain if
1625the default environment is used; a new CRC is computed as soon as you
1626use the "saveenv" command to store a valid environment.
1627
1628
1629Low Level (hardware related) configuration options:
1630---------------------------------------------------
1631
1632- CFG_CACHELINE_SIZE:
1633		Cache Line Size of the CPU.
1634
1635- CFG_DEFAULT_IMMR:
1636		Default address of the IMMR after system reset.
1637		Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1638		to be able to adjust the position of the IMMR
1639		register after a reset.
1640
1641- Floppy Disk Support:
1642		CFG_FDC_DRIVE_NUMBER
1643
1644		the default drive number (default value 0)
1645
1646		CFG_ISA_IO_STRIDE
1647
1648		defines the spacing between fdc chipset registers
1649		(default value 1)
1650
1651		CFG_ISA_IO_OFFSET
1652
1653		defines the offset of register from address. It
1654		depends on which part of the data bus is connected to
1655		the fdc chipset. (default value 0)
1656
1657		If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
1658		CFG_FDC_DRIVE_NUMBER are undefined, they take their
1659		default value.
1660
1661		if CFG_FDC_HW_INIT is defined, then the function
1662		fdc_hw_init() is called at the beginning of the FDC
1663		setup. fdc_hw_init() must be provided by the board
1664		source code. It is used to make hardware dependant
1665		initializations.
1666
1667- CFG_IMMR:	Physical address of the Internal Memory Mapped
1668		Register; DO NOT CHANGE! (11-4)
1669		[MPC8xx systems only]
1670
1671- CFG_INIT_RAM_ADDR:
1672
1673		Start address of memory area tha can be used for
1674		initial data and stack; please note that this must be
1675		writable memory that is working WITHOUT special
1676		initialization, i. e. you CANNOT use normal RAM which
1677		will become available only after programming the
1678		memory controller and running certain initialization
1679		sequences.
1680
1681		U-Boot uses the following memory types:
1682		- MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1683		- MPC824X: data cache
1684		- PPC4xx:  data cache
1685
1686- CFG_GBL_DATA_OFFSET:
1687
1688		Offset of the initial data structure in the memory
1689		area defined by CFG_INIT_RAM_ADDR. Usually
1690		CFG_GBL_DATA_OFFSET is chosen such that the initial
1691		data is located at the end of the available space
1692		(sometimes written as (CFG_INIT_RAM_END -
1693		CFG_INIT_DATA_SIZE), and the initial stack is just
1694		below that area (growing from (CFG_INIT_RAM_ADDR +
1695		CFG_GBL_DATA_OFFSET) downward.
1696
1697	Note:
1698		On the MPC824X (or other systems that use the data
1699		cache for initial memory) the address chosen for
1700		CFG_INIT_RAM_ADDR is basically arbitrary - it must
1701		point to an otherwise UNUSED address space between
1702		the top of RAM and the start of the PCI space.
1703
1704- CFG_SIUMCR:	SIU Module Configuration (11-6)
1705
1706- CFG_SYPCR:	System Protection Control (11-9)
1707
1708- CFG_TBSCR:	Time Base Status and Control (11-26)
1709
1710- CFG_PISCR:	Periodic Interrupt Status and Control (11-31)
1711
1712- CFG_PLPRCR:	PLL, Low-Power, and Reset Control Register (15-30)
1713
1714- CFG_SCCR:	System Clock and reset Control Register (15-27)
1715
1716- CFG_OR_TIMING_SDRAM:
1717		SDRAM timing
1718
1719- CFG_MAMR_PTA:
1720		periodic timer for refresh
1721
1722- CFG_DER:	Debug Event Register (37-47)
1723
1724- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1725  CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1726  CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1727  CFG_BR1_PRELIM:
1728		Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1729
1730- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1731  CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1732  CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1733		Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1734
1735- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1736  CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1737		Machine Mode Register and Memory Periodic Timer
1738		Prescaler definitions (SDRAM timing)
1739
1740- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1741		enable I2C microcode relocation patch (MPC8xx);
1742		define relocation offset in DPRAM [DSP2]
1743
1744- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1745		enable SPI microcode relocation patch (MPC8xx);
1746		define relocation offset in DPRAM [SCC4]
1747
1748- CFG_USE_OSCCLK:
1749		Use OSCM clock mode on MBX8xx board. Be careful,
1750		wrong setting might damage your board. Read
1751		doc/README.MBX before setting this variable!
1752
1753- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1754		Offset of the bootmode word in DPRAM used by post
1755		(Power On Self Tests). This definition overrides
1756		#define'd default value in commproc.h resp.
1757		cpm_8260.h.
1758
1759- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
1760  CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
1761  CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
1762  CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
1763  CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
1764  CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
1765  CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
1766  CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
1767		Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
1768
1769Building the Software:
1770======================
1771
1772Building U-Boot has been tested in native PPC environments (on a
1773PowerBook G3 running LinuxPPC 2000) and in cross environments
1774(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1775NetBSD 1.5 on x86).
1776
1777If you are not using a native PPC environment, it is assumed that you
1778have the GNU cross compiling tools available in your path and named
1779with a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1780you are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1781the definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1782change it to:
1783
1784	CROSS_COMPILE = ppc_4xx-
1785
1786
1787U-Boot is intended to be  simple  to  build.  After  installing  the
1788sources	 you must configure U-Boot for one specific board type. This
1789is done by typing:
1790
1791	make NAME_config
1792
1793where "NAME_config" is the name of one of the existing
1794configurations; the following names are supported:
1795
1796    ADCIOP_config	  GTH_config		TQM850L_config
1797    ADS860_config	  IP860_config		TQM855L_config
1798    AR405_config	  IVML24_config		TQM860L_config
1799    CANBT_config	  IVMS8_config		WALNUT405_config
1800    CPCI405_config	  LANTEC_config		cogent_common_config
1801    CPCIISER4_config	  MBX_config		cogent_mpc8260_config
1802    CU824_config	  MBX860T_config	cogent_mpc8xx_config
1803    ESTEEM192E_config	  RPXlite_config	hermes_config
1804    ETX094_config	  RPXsuper_config	hymod_config
1805    FADS823_config	  SM850_config		lwmon_config
1806    FADS850SAR_config	  SPD823TS_config	pcu_e_config
1807    FADS860T_config	  SXNI855T_config	rsdproto_config
1808    FPS850L_config	  Sandpoint8240_config	sbc8260_config
1809    GENIETV_config	  TQM823L_config	PIP405_config
1810    GEN860T_config	  EBONY_config		FPS860L_config
1811    ELPT860_config	  cmi_mpc5xx_config	NETVIA_config
1812    at91rm9200dk_config
1813
1814Note: for some board special configuration names may exist; check  if
1815      additional  information is available from the board vendor; for
1816      instance, the TQM8xxL systems run normally at 50 MHz and use  a
1817      SCC  for	10baseT	 ethernet; there are also systems with 80 MHz
1818      CPU clock, and an optional Fast Ethernet	module	is  available
1819      for  CPU's  with FEC. You can select such additional "features"
1820      when chosing the configuration, i. e.
1821
1822      make TQM860L_config
1823	- will configure for a plain TQM860L, i. e. 50MHz, no FEC
1824
1825      make TQM860L_FEC_config
1826	- will configure for a TQM860L at 50MHz with FEC for ethernet
1827
1828      make TQM860L_80MHz_config
1829	- will configure for a TQM860L at 80 MHz, with normal 10baseT
1830	  interface
1831
1832      make TQM860L_FEC_80MHz_config
1833	- will configure for a TQM860L at 80 MHz with FEC for ethernet
1834
1835      make TQM823L_LCD_config
1836	- will configure for a TQM823L with U-Boot console on LCD
1837
1838      make TQM823L_LCD_80MHz_config
1839	- will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1840
1841      etc.
1842
1843
1844
1845Finally, type "make all", and you should get some working U-Boot
1846images ready for downlod to / installation on your system:
1847
1848- "u-boot.bin" is a raw binary image
1849- "u-boot" is an image in ELF binary format
1850- "u-boot.srec" is in Motorola S-Record format
1851
1852
1853Please be aware that the Makefiles assume you are using GNU make, so
1854for instance on NetBSD you might need to use "gmake" instead of
1855native "make".
1856
1857
1858If the system board that you have is not listed, then you will need
1859to port U-Boot to your hardware platform. To do this, follow these
1860steps:
1861
18621.  Add a new configuration option for your board to the toplevel
1863    "Makefile" and to the "MAKEALL" script, using the existing
1864    entries as examples. Note that here and at many other places
1865    boards and other names are listed alphabetically sorted. Please
1866    keep this order.
18672.  Create a new directory to hold your board specific code. Add any
1868    files you need. In your board directory, you will need at least
1869    the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
18703.  Create a new configuration file "include/configs/<board>.h" for
1871    your board
18723.  If you're porting U-Boot to a new CPU, then also create a new
1873    directory to hold your CPU specific code. Add any files you need.
18744.  Run "make <board>_config" with your new name.
18755.  Type "make", and you should get a working "u-boot.srec" file
1876    to be installed on your target system.
18776.  Debug and solve any problems that might arise.
1878    [Of course, this last step is much harder than it sounds.]
1879
1880
1881Testing of U-Boot Modifications, Ports to New Hardware, etc.:
1882==============================================================
1883
1884If you have modified U-Boot sources (for instance added a new	board
1885or  support  for  new  devices,	 a new CPU, etc.) you are expected to
1886provide feedback to the other developers. The feedback normally takes
1887the form of a "patch", i. e. a context diff against a certain (latest
1888official or latest in CVS) version of U-Boot sources.
1889
1890But before you submit such a patch, please verify that	your  modifi-
1891cation	did not break existing code. At least make sure that *ALL* of
1892the supported boards compile WITHOUT ANY compiler warnings. To do so,
1893just run the "MAKEALL" script, which will configure and build U-Boot
1894for ALL supported system. Be warned, this will take a while. You  can
1895select	which  (cross)	compiler  to use py passing a `CROSS_COMPILE'
1896environment variable to the script, i. e. to use the cross tools from
1897MontaVista's Hard Hat Linux you can type
1898
1899	CROSS_COMPILE=ppc_8xx- MAKEALL
1900
1901or to build on a native PowerPC system you can type
1902
1903	CROSS_COMPILE=' ' MAKEALL
1904
1905See also "U-Boot Porting Guide" below.
1906
1907
1908
1909Monitor Commands - Overview:
1910============================
1911
1912go	- start application at address 'addr'
1913run	- run commands in an environment variable
1914bootm	- boot application image from memory
1915bootp	- boot image via network using BootP/TFTP protocol
1916tftpboot- boot image via network using TFTP protocol
1917	       and env variables "ipaddr" and "serverip"
1918	       (and eventually "gatewayip")
1919rarpboot- boot image via network using RARP/TFTP protocol
1920diskboot- boot from IDE devicebootd   - boot default, i.e., run 'bootcmd'
1921loads	- load S-Record file over serial line
1922loadb	- load binary file over serial line (kermit mode)
1923md	- memory display
1924mm	- memory modify (auto-incrementing)
1925nm	- memory modify (constant address)
1926mw	- memory write (fill)
1927cp	- memory copy
1928cmp	- memory compare
1929crc32	- checksum calculation
1930imd     - i2c memory display
1931imm     - i2c memory modify (auto-incrementing)
1932inm     - i2c memory modify (constant address)
1933imw     - i2c memory write (fill)
1934icrc32  - i2c checksum calculation
1935iprobe  - probe to discover valid I2C chip addresses
1936iloop   - infinite loop on address range
1937isdram  - print SDRAM configuration information
1938sspi    - SPI utility commands
1939base	- print or set address offset
1940printenv- print environment variables
1941setenv	- set environment variables
1942saveenv - save environment variables to persistent storage
1943protect - enable or disable FLASH write protection
1944erase	- erase FLASH memory
1945flinfo	- print FLASH memory information
1946bdinfo	- print Board Info structure
1947iminfo	- print header information for application image
1948coninfo - print console devices and informations
1949ide	- IDE sub-system
1950loop	- infinite loop on address range
1951mtest	- simple RAM test
1952icache	- enable or disable instruction cache
1953dcache	- enable or disable data cache
1954reset	- Perform RESET of the CPU
1955echo	- echo args to console
1956version - print monitor version
1957help	- print online help
1958?	- alias for 'help'
1959
1960
1961Monitor Commands - Detailed Description:
1962========================================
1963
1964TODO.
1965
1966For now: just type "help <command>".
1967
1968
1969Environment Variables:
1970======================
1971
1972U-Boot supports user configuration using Environment Variables which
1973can be made persistent by saving to Flash memory.
1974
1975Environment Variables are set using "setenv", printed using
1976"printenv", and saved to Flash using "saveenv". Using "setenv"
1977without a value can be used to delete a variable from the
1978environment. As long as you don't save the environment you are
1979working with an in-memory copy. In case the Flash area containing the
1980environment is erased by accident, a default environment is provided.
1981
1982Some configuration options can be set using Environment Variables:
1983
1984  baudrate	- see CONFIG_BAUDRATE
1985
1986  bootdelay	- see CONFIG_BOOTDELAY
1987
1988  bootcmd	- see CONFIG_BOOTCOMMAND
1989
1990  bootargs	- Boot arguments when booting an RTOS image
1991
1992  bootfile	- Name of the image to load with TFTP
1993
1994  autoload	- if set to "no" (any string beginning with 'n'),
1995		  "bootp" will just load perform a lookup of the
1996		  configuration from the BOOTP server, but not try to
1997		  load any image using TFTP
1998
1999  autostart	- if set to "yes", an image loaded using the "bootp",
2000		  "rarpboot", "tftpboot" or "diskboot" commands will
2001		  be automatically started (by internally calling
2002		  "bootm")
2003
2004		  If set to "no", a standalone image passed to the
2005		  "bootm" command will be copied to the load address
2006		  (and eventually uncompressed), but NOT be started.
2007		  This can be used to load and uncompress arbitrary
2008		  data.
2009
2010  initrd_high	- restrict positioning of initrd images:
2011		  If this variable is not set, initrd images will be
2012		  copied to the highest possible address in RAM; this
2013		  is usually what you want since it allows for
2014		  maximum initrd size. If for some reason you want to
2015		  make sure that the initrd image is loaded below the
2016		  CFG_BOOTMAPSZ limit, you can set this environment
2017		  variable to a value of "no" or "off" or "0".
2018		  Alternatively, you can set it to a maximum upper
2019		  address to use (U-Boot will still check that it
2020		  does not overwrite the U-Boot stack and data).
2021
2022		  For instance, when you have a system with 16 MB
2023		  RAM, and want to reseve 4 MB from use by Linux,
2024		  you can do this by adding "mem=12M" to the value of
2025		  the "bootargs" variable. However, now you must make
2026		  sure, that the initrd image is placed in the first
2027		  12 MB as well - this can be done with
2028
2029		  setenv initrd_high 00c00000
2030
2031                  If you set initrd_high to 0xFFFFFFFF, this is an
2032                  indication to U-Boot that all addresses are legal
2033                  for the Linux kernel, including addresses in flash
2034                  memory. In this case U-Boot will NOT COPY the
2035                  ramdisk at all. This may be useful to reduce the
2036                  boot time on your system, but requires that this
2037                  feature is supported by your Linux kernel.
2038
2039  ipaddr	- IP address; needed for tftpboot command
2040
2041  loadaddr	- Default load address for commands like "bootp",
2042		  "rarpboot", "tftpboot", "loadb" or "diskboot"
2043
2044  loads_echo	- see CONFIG_LOADS_ECHO
2045
2046  serverip	- TFTP server IP address; needed for tftpboot command
2047
2048  bootretry	- see CONFIG_BOOT_RETRY_TIME
2049
2050  bootdelaykey	- see CONFIG_AUTOBOOT_DELAY_STR
2051
2052  bootstopkey	- see CONFIG_AUTOBOOT_STOP_STR
2053
2054
2055The following environment variables may be used and automatically
2056updated by the network boot commands ("bootp" and "rarpboot"),
2057depending the information provided by your boot server:
2058
2059  bootfile	- see above
2060  dnsip		- IP address of your Domain Name Server
2061  gatewayip	- IP address of the Gateway (Router) to use
2062  hostname	- Target hostname
2063  ipaddr	- see above
2064  netmask	- Subnet Mask
2065  rootpath	- Pathname of the root filesystem on the NFS server
2066  serverip	- see above
2067
2068
2069There are two special Environment Variables:
2070
2071  serial#	- contains hardware identification information such
2072		  as type string and/or serial number
2073  ethaddr	- Ethernet address
2074
2075These variables can be set only once (usually during manufacturing of
2076the board). U-Boot refuses to delete or overwrite these variables
2077once they have been set once.
2078
2079
2080Further special Environment Variables:
2081
2082  ver		- Contains the U-Boot version string as printed
2083		  with the "version" command. This variable is
2084		  readonly (see CONFIG_VERSION_VARIABLE).
2085
2086
2087Please note that changes to some configuration parameters may take
2088only effect after the next boot (yes, that's just like Windoze :-).
2089
2090
2091Command Line Parsing:
2092=====================
2093
2094There are two different command line parsers available  with  U-Boot:
2095the old "simple" one, and the much more pwerful "hush" shell:
2096
2097Old, simple command line parser:
2098--------------------------------
2099
2100- supports environment variables (through setenv / saveenv commands)
2101- several commands on one line, separated by ';'
2102- variable substitution using "... $(name) ..." syntax
2103- special characters ('$', ';') can be escaped by prefixing with '\',
2104  for example:
2105	setenv bootcmd bootm \$(address)
2106- You can also escape text by enclosing in single apostrophes, for example:
2107	setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2108
2109Hush shell:
2110-----------
2111
2112- similar to Bourne shell, with control structures like
2113  if...then...else...fi, for...do...done; while...do...done,
2114  until...do...done, ...
2115- supports environment ("global") variables (through setenv / saveenv
2116  commands) and local shell variables (through standard shell syntax
2117  "name=value"); only environment variables can be used with "run"
2118  command
2119
2120General rules:
2121--------------
2122
2123(1) If a command line (or an environment variable executed by a "run"
2124    command) contains several commands separated by semicolon, and
2125    one of these commands fails, then the remaining commands will be
2126    executed anyway.
2127
2128(2) If you execute several variables with one call to run (i. e.
2129    calling run with a list af variables as arguments), any failing
2130    command will cause "run" to terminate, i. e. the remaining
2131    variables are not executed.
2132
2133Note for Redundant Ethernet Interfaces:
2134=======================================
2135
2136Some boards come with redundand ethernet interfaces; U-Boot supports
2137such configurations and is capable of automatic selection of a
2138"working" interface when needed. MAC assignemnt works as follows:
2139
2140Network interfaces are numbered eth0, eth1, eth2, ... Corresponding
2141MAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2142"eth1addr" (=>eth1), "eth2addr", ...
2143
2144If the network interface stores some valid MAC address (for instance
2145in SROM), this is used as default address if there is NO correspon-
2146ding setting in the environment; if the corresponding environment
2147variable is set, this overrides the settings in the card; that means:
2148
2149o If the SROM has a valid MAC address, and there is no address in the
2150  environment, the SROM's address is used.
2151
2152o If there is no valid address in the SROM, and a definition in the
2153  environment exists, then the value from the environment variable is
2154  used.
2155
2156o If both the SROM and the environment contain a MAC address, and
2157  both addresses are the same, this MAC address is used.
2158
2159o If both the SROM and the environment contain a MAC address, and the
2160  addresses differ, the value from the environment is used and a
2161  warning is printed.
2162
2163o If neither SROM nor the environment contain a MAC address, an error
2164  is raised.
2165
2166
2167
2168Image Formats:
2169==============
2170
2171The "boot" commands of this monitor operate on "image" files which
2172can be basicly anything, preceeded by a special header; see the
2173definitions in include/image.h for details; basicly, the header
2174defines the following image properties:
2175
2176* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2177  4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2178  LynxOS, pSOS, QNX, RTEMS, ARTOS;
2179  Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS).
2180* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2181  IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2182  Currently supported: PowerPC).
2183* Compression Type (Provisions for uncompressed, gzip, bzip2;
2184  Currently supported: uncompressed, gzip).
2185* Load Address
2186* Entry Point
2187* Image Name
2188* Image Timestamp
2189
2190The header is marked by a special Magic Number, and both the header
2191and the data portions of the image are secured against corruption by
2192CRC32 checksums.
2193
2194
2195Linux Support:
2196==============
2197
2198Although U-Boot should support any OS or standalone application
2199easily, Linux has always been in the focus during the design of
2200U-Boot.
2201
2202U-Boot includes many features that so far have been part of some
2203special "boot loader" code within the Linux kernel. Also, any
2204"initrd" images to be used are no longer part of one big Linux image;
2205instead, kernel and "initrd" are separate images. This implementation
2206serves serveral purposes:
2207
2208- the same features can be used for other OS or standalone
2209  applications (for instance: using compressed images to reduce the
2210  Flash memory footprint)
2211
2212- it becomes much easier to port new Linux kernel versions because
2213  lots of low-level, hardware dependend stuff are done by U-Boot
2214
2215- the same Linux kernel image can now be used with different "initrd"
2216  images; of course this also means that different kernel images can
2217  be run with the same "initrd". This makes testing easier (you don't
2218  have to build a new "zImage.initrd" Linux image when you just
2219  change a file in your "initrd"). Also, a field-upgrade of the
2220  software is easier now.
2221
2222
2223Linux HOWTO:
2224============
2225
2226Porting Linux to U-Boot based systems:
2227---------------------------------------
2228
2229U-Boot cannot save you from doing all the necessary modifications to
2230configure the Linux device drivers for use with your target hardware
2231(no, we don't intend to provide a full virtual machine interface to
2232Linux :-).
2233
2234But now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2235
2236Just make sure your machine specific header file (for instance
2237include/asm-ppc/tqm8xx.h) includes the same definition of the Board
2238Information structure as we define in include/u-boot.h, and make
2239sure that your definition of IMAP_ADDR uses the same value as your
2240U-Boot configuration in CFG_IMMR.
2241
2242
2243Configuring the Linux kernel:
2244-----------------------------
2245
2246No specific requirements for U-Boot. Make sure you have some root
2247device (initial ramdisk, NFS) for your target system.
2248
2249
2250Building a Linux Image:
2251-----------------------
2252
2253With U-Boot, "normal" build targets like "zImage" or "bzImage" are
2254not used. If you use recent kernel source, a new build target
2255"uImage" will exist which automatically builds an image usable by
2256U-Boot. Most older kernels also have support for a "pImage" target,
2257which was introduced for our predecessor project PPCBoot and uses a
2258100% compatible format.
2259
2260Example:
2261
2262	make TQM850L_config
2263	make oldconfig
2264	make dep
2265	make uImage
2266
2267The "uImage" build target uses a special tool (in 'tools/mkimage') to
2268encapsulate a compressed Linux kernel image with header  information,
2269CRC32 checksum etc. for use with U-Boot. This is what we are doing:
2270
2271* build a standard "vmlinux" kernel image (in ELF binary format):
2272
2273* convert the kernel into a raw binary image:
2274
2275	${CROSS_COMPILE}-objcopy -O binary \
2276				 -R .note -R .comment \
2277				 -S vmlinux linux.bin
2278
2279* compress the binary image:
2280
2281	gzip -9 linux.bin
2282
2283* package compressed binary image for U-Boot:
2284
2285	mkimage -A ppc -O linux -T kernel -C gzip \
2286		-a 0 -e 0 -n "Linux Kernel Image" \
2287		-d linux.bin.gz uImage
2288
2289
2290The "mkimage" tool can also be used to create ramdisk images for use
2291with U-Boot, either separated from the Linux kernel image, or
2292combined into one file. "mkimage" encapsulates the images with a 64
2293byte header containing information about target architecture,
2294operating system, image type, compression method, entry points, time
2295stamp, CRC32 checksums, etc.
2296
2297"mkimage" can be called in two ways: to verify existing images and
2298print the header information, or to build new images.
2299
2300In the first form (with "-l" option) mkimage lists the information
2301contained in the header of an existing U-Boot image; this includes
2302checksum verification:
2303
2304	tools/mkimage -l image
2305	  -l ==> list image header information
2306
2307The second form (with "-d" option) is used to build a U-Boot image
2308from a "data file" which is used as image payload:
2309
2310	tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2311		      -n name -d data_file image
2312	  -A ==> set architecture to 'arch'
2313	  -O ==> set operating system to 'os'
2314	  -T ==> set image type to 'type'
2315	  -C ==> set compression type 'comp'
2316	  -a ==> set load address to 'addr' (hex)
2317	  -e ==> set entry point to 'ep' (hex)
2318	  -n ==> set image name to 'name'
2319	  -d ==> use image data from 'datafile'
2320
2321Right now, all Linux kernels use the same load address	(0x00000000),
2322but the entry point address depends on the kernel version:
2323
2324- 2.2.x kernels have the entry point at 0x0000000C,
2325- 2.3.x and later kernels have the entry point at 0x00000000.
2326
2327So a typical call to build a U-Boot image would read:
2328
2329	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2330	> -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
2331	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
2332	> examples/uImage.TQM850L
2333	Image Name:   2.4.4 kernel for TQM850L
2334	Created:      Wed Jul 19 02:34:59 2000
2335	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2336	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2337	Load Address: 0x00000000
2338	Entry Point:  0x00000000
2339
2340To verify the contents of the image (or check for corruption):
2341
2342	-> tools/mkimage -l examples/uImage.TQM850L
2343	Image Name:   2.4.4 kernel for TQM850L
2344	Created:      Wed Jul 19 02:34:59 2000
2345	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2346	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2347	Load Address: 0x00000000
2348	Entry Point:  0x00000000
2349
2350NOTE: for embedded systems where boot time is critical you can trade
2351speed for memory and install an UNCOMPRESSED image instead: this
2352needs more space in Flash, but boots much faster since it does not
2353need to be uncompressed:
2354
2355	-> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
2356	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
2357	> -A ppc -O linux -T kernel -C none -a 0 -e 0 \
2358	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
2359	> examples/uImage.TQM850L-uncompressed
2360	Image Name:   2.4.4 kernel for TQM850L
2361	Created:      Wed Jul 19 02:34:59 2000
2362	Image Type:   PowerPC Linux Kernel Image (uncompressed)
2363	Data Size:    792160 Bytes = 773.59 kB = 0.76 MB
2364	Load Address: 0x00000000
2365	Entry Point:  0x00000000
2366
2367
2368Similar you can build U-Boot images from a 'ramdisk.image.gz' file
2369when your kernel is intended to use an initial ramdisk:
2370
2371	-> tools/mkimage -n 'Simple Ramdisk Image' \
2372	> -A ppc -O linux -T ramdisk -C gzip \
2373	> -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2374	Image Name:   Simple Ramdisk Image
2375	Created:      Wed Jan 12 14:01:50 2000
2376	Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)
2377	Data Size:    566530 Bytes = 553.25 kB = 0.54 MB
2378	Load Address: 0x00000000
2379	Entry Point:  0x00000000
2380
2381
2382Installing a Linux Image:
2383-------------------------
2384
2385To downloading a U-Boot image over the serial (console) interface,
2386you must convert the image to S-Record format:
2387
2388	objcopy -I binary -O srec examples/image examples/image.srec
2389
2390The 'objcopy' does not understand the information in the U-Boot
2391image header, so the resulting S-Record file will be relative to
2392address 0x00000000. To load it to a given address, you need to
2393specify the target address as 'offset' parameter with the 'loads'
2394command.
2395
2396Example: install the image to address 0x40100000 (which on the
2397TQM8xxL is in the first Flash bank):
2398
2399	=> erase 40100000 401FFFFF
2400
2401	.......... done
2402	Erased 8 sectors
2403
2404	=> loads 40100000
2405	## Ready for S-Record download ...
2406	~>examples/image.srec
2407	1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2408	...
2409	15989 15990 15991 15992
2410	[file transfer complete]
2411	[connected]
2412	## Start Addr = 0x00000000
2413
2414
2415You can check the success of the download using the 'iminfo' command;
2416this includes a checksum verification so you  can  be  sure  no	 data
2417corruption happened:
2418
2419	=> imi 40100000
2420
2421	## Checking Image at 40100000 ...
2422	   Image Name:	 2.2.13 for initrd on TQM850L
2423	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2424	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2425	   Load Address: 00000000
2426	   Entry Point:	 0000000c
2427	   Verifying Checksum ... OK
2428
2429
2430
2431Boot Linux:
2432-----------
2433
2434The "bootm" command is used to boot an application that is stored in
2435memory (RAM or Flash). In case of a Linux kernel image, the contents
2436of the "bootargs" environment variable is passed to the kernel as
2437parameters. You can check and modify this variable using the
2438"printenv" and "setenv" commands:
2439
2440
2441	=> printenv bootargs
2442	bootargs=root=/dev/ram
2443
2444	=> setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2445
2446	=> printenv bootargs
2447	bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2448
2449	=> bootm 40020000
2450	## Booting Linux kernel at 40020000 ...
2451	   Image Name:	 2.2.13 for NFS on TQM850L
2452	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2453	   Data Size:	 381681 Bytes = 372 kB = 0 MB
2454	   Load Address: 00000000
2455	   Entry Point:	 0000000c
2456	   Verifying Checksum ... OK
2457	   Uncompressing Kernel Image ... OK
2458	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
2459	Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2460	time_init: decrementer frequency = 187500000/60
2461	Calibrating delay loop... 49.77 BogoMIPS
2462	Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2463	...
2464
2465If you want to boot a Linux kernel with initial ram disk, you pass
2466the memory addreses of both the kernel and the initrd image (PPBCOOT
2467format!) to the "bootm" command:
2468
2469	=> imi 40100000 40200000
2470
2471	## Checking Image at 40100000 ...
2472	   Image Name:	 2.2.13 for initrd on TQM850L
2473	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2474	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2475	   Load Address: 00000000
2476	   Entry Point:	 0000000c
2477	   Verifying Checksum ... OK
2478
2479	## Checking Image at 40200000 ...
2480	   Image Name:	 Simple Ramdisk Image
2481	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2482	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2483	   Load Address: 00000000
2484	   Entry Point:	 00000000
2485	   Verifying Checksum ... OK
2486
2487	=> bootm 40100000 40200000
2488	## Booting Linux kernel at 40100000 ...
2489	   Image Name:	 2.2.13 for initrd on TQM850L
2490	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2491	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2492	   Load Address: 00000000
2493	   Entry Point:	 0000000c
2494	   Verifying Checksum ... OK
2495	   Uncompressing Kernel Image ... OK
2496	## Loading RAMDisk Image at 40200000 ...
2497	   Image Name:	 Simple Ramdisk Image
2498	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2499	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2500	   Load Address: 00000000
2501	   Entry Point:	 00000000
2502	   Verifying Checksum ... OK
2503	   Loading Ramdisk ... OK
2504	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
2505	Boot arguments: root=/dev/ram
2506	time_init: decrementer frequency = 187500000/60
2507	Calibrating delay loop... 49.77 BogoMIPS
2508	...
2509	RAMDISK: Compressed image found at block 0
2510	VFS: Mounted root (ext2 filesystem).
2511
2512	bash#
2513
2514More About U-Boot Image Types:
2515------------------------------
2516
2517U-Boot supports the following image types:
2518
2519   "Standalone Programs" are directly runnable in the environment
2520  	provided by U-Boot; it is expected that (if they behave
2521  	well) you can continue to work in U-Boot after return from
2522  	the Standalone Program.
2523   "OS Kernel Images" are usually images of some Embedded OS which
2524  	will take over control completely. Usually these programs
2525  	will install their own set of exception handlers, device
2526  	drivers, set up the MMU, etc. - this means, that you cannot
2527  	expect to re-enter U-Boot except by resetting the CPU.
2528   "RAMDisk Images" are more or less just data blocks, and their
2529  	parameters (address, size) are passed to an OS kernel that is
2530  	being started.
2531   "Multi-File Images" contain several images, typically an OS
2532  	(Linux) kernel image and one or more data images like
2533  	RAMDisks. This construct is useful for instance when you want
2534  	to boot over the network using BOOTP etc., where the boot
2535  	server provides just a single image file, but you want to get
2536  	for instance an OS kernel and a RAMDisk image.
2537
2538  	"Multi-File Images" start with a list of image sizes, each
2539  	image size (in bytes) specified by an "uint32_t" in network
2540  	byte order. This list is terminated by an "(uint32_t)0".
2541  	Immediately after the terminating 0 follow the images, one by
2542  	one, all aligned on "uint32_t" boundaries (size rounded up to
2543  	a multiple of 4 bytes).
2544
2545   "Firmware Images" are binary images containing firmware (like
2546  	U-Boot or FPGA images) which usually will be programmed to
2547  	flash memory.
2548
2549   "Script files" are command sequences that will be executed by
2550  	U-Boot's command interpreter; this feature is especially
2551  	useful when you configure U-Boot to use a real shell (hush)
2552  	as command interpreter.
2553
2554
2555Standalone HOWTO:
2556=================
2557
2558One of the features of U-Boot is that you can dynamically load and
2559run "standalone" applications, which can use some resources of
2560U-Boot like console I/O functions or interrupt services.
2561
2562Two simple examples are included with the sources:
2563
2564"Hello World" Demo:
2565-------------------
2566
2567'examples/hello_world.c' contains a small "Hello World" Demo
2568application; it is automatically compiled when you build U-Boot.
2569It's configured to run at address 0x00040004, so you can play with it
2570like that:
2571
2572	=> loads
2573	## Ready for S-Record download ...
2574	~>examples/hello_world.srec
2575	1 2 3 4 5 6 7 8 9 10 11 ...
2576	[file transfer complete]
2577	[connected]
2578	## Start Addr = 0x00040004
2579
2580	=> go 40004 Hello World! This is a test.
2581	## Starting application at 0x00040004 ...
2582	Hello World
2583	argc = 7
2584	argv[0] = "40004"
2585	argv[1] = "Hello"
2586	argv[2] = "World!"
2587	argv[3] = "This"
2588	argv[4] = "is"
2589	argv[5] = "a"
2590	argv[6] = "test."
2591	argv[7] = "<NULL>"
2592	Hit any key to exit ...
2593
2594	## Application terminated, rc = 0x0
2595
2596Another example, which demonstrates how to register a CPM interrupt
2597handler with the U-Boot code, can be found in 'examples/timer.c'.
2598Here, a CPM timer is set up to generate an interrupt every second.
2599The interrupt service routine is trivial, just printing a '.'
2600character, but this is just a demo program. The application can be
2601controlled by the following keys:
2602
2603	? - print current values og the CPM Timer registers
2604	b - enable interrupts and start timer
2605	e - stop timer and disable interrupts
2606	q - quit application
2607
2608	=> loads
2609	## Ready for S-Record download ...
2610	~>examples/timer.srec
2611	1 2 3 4 5 6 7 8 9 10 11 ...
2612	[file transfer complete]
2613	[connected]
2614	## Start Addr = 0x00040004
2615
2616	=> go 40004
2617	## Starting application at 0x00040004 ...
2618	TIMERS=0xfff00980
2619	Using timer 1
2620	  tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2621
2622Hit 'b':
2623	[q, b, e, ?] Set interval 1000000 us
2624	Enabling timer
2625Hit '?':
2626	[q, b, e, ?] ........
2627	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2628Hit '?':
2629	[q, b, e, ?] .
2630	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2631Hit '?':
2632	[q, b, e, ?] .
2633	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2634Hit '?':
2635	[q, b, e, ?] .
2636	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2637Hit 'e':
2638	[q, b, e, ?] ...Stopping timer
2639Hit 'q':
2640	[q, b, e, ?] ## Application terminated, rc = 0x0
2641
2642
2643
2644Minicom warning:
2645================
2646
2647Over time, many people have reported problems when trying to used the
2648"minicom" terminal emulation program for serial download. I (wd)
2649consider minicom to be broken, and recommend not to use it. Under
2650Unix, I recommend to use C-Kermit for general purpose use (and
2651especially for kermit binary protocol download ("loadb" command), and
2652use "cu" for S-Record download ("loads" command).
2653
2654Nevertheless, if you absolutely want to use it try adding this
2655configuration to your "File transfer protocols" section:
2656
2657	   Name    Program                      Name U/D FullScr IO-Red. Multi
2658	X  kermit  /usr/bin/kermit -i -l %l -s   Y    U    Y       N      N
2659	Y  kermit  /usr/bin/kermit -i -l %l -r   N    D    Y       N      N
2660
2661
2662NetBSD Notes:
2663=============
2664
2665Starting at version 0.9.2, U-Boot supports NetBSD both as host
2666(build U-Boot) and target system (boots NetBSD/mpc8xx).
2667
2668Building requires a cross environment; it is known to work on
2669NetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2670need gmake since the Makefiles are not compatible with BSD make).
2671Note that the cross-powerpc package does not install include files;
2672attempting to build U-Boot will fail because <machine/ansi.h> is
2673missing.  This file has to be installed and patched manually:
2674
2675	# cd /usr/pkg/cross/powerpc-netbsd/include
2676	# mkdir powerpc
2677	# ln -s powerpc machine
2678	# cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2679	# ${EDIT} powerpc/ansi.h	## must remove __va_list, _BSD_VA_LIST
2680
2681Native builds *don't* work due to incompatibilities between native
2682and U-Boot include files.
2683
2684Booting assumes that (the first part of) the image booted is a
2685stage-2 loader which in turn loads and then invokes the kernel
2686proper. Loader sources will eventually appear in the NetBSD source
2687tree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2688meantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2689details.
2690
2691
2692Implementation Internals:
2693=========================
2694
2695The following is not intended to be a complete description of every
2696implementation detail. However, it should help to understand the
2697inner workings of U-Boot and make it easier to port it to custom
2698hardware.
2699
2700
2701Initial Stack, Global Data:
2702---------------------------
2703
2704The implementation of U-Boot is complicated by the fact that U-Boot
2705starts running out of ROM (flash memory), usually without access to
2706system RAM (because the memory controller is not initialized yet).
2707This means that we don't have writable Data or BSS segments, and BSS
2708is not initialized as zero. To be able to get a C environment working
2709at all, we have to allocate at least a minimal stack. Implementation
2710options for this are defined and restricted by the CPU used: Some CPU
2711models provide on-chip memory (like the IMMR area on MPC8xx and
2712MPC826x processors), on others (parts of) the data cache can be
2713locked as (mis-) used as memory, etc.
2714
2715	Chris Hallinan posted a good summy of  these  issues  to  the
2716	u-boot-users mailing list:
2717
2718	Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2719	From: "Chris Hallinan" <clh@net1plus.com>
2720	Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2721	...
2722
2723	Correct me if I'm wrong, folks, but the way I understand it
2724	is this: Using DCACHE as initial RAM for Stack, etc, does not
2725	require any physical RAM backing up the cache. The cleverness
2726	is that the cache is being used as a temporary supply of
2727	necessary storage before the SDRAM controller is setup. It's
2728	beyond the scope of this list to expain the details, but you
2729	can see how this works by studying the cache architecture and
2730	operation in the architecture and processor-specific manuals.
2731
2732	OCM is On Chip Memory, which I believe the 405GP has 4K. It
2733	is another option for the system designer to use as an
2734	initial stack/ram area prior to SDRAM being available. Either
2735	option should work for you. Using CS 4 should be fine if your
2736	board designers haven't used it for something that would
2737	cause you grief during the initial boot! It is frequently not
2738	used.
2739
2740	CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2741	with your processor/board/system design. The default value
2742	you will find in any recent u-boot distribution in
2743	Walnut405.h should work for you. I'd set it to a value larger
2744	than your SDRAM module. If you have a 64MB SDRAM module, set
2745	it above 400_0000. Just make sure your board has no resources
2746	that are supposed to respond to that address! That code in
2747	start.S has been around a while and should work as is when
2748	you get the config right.
2749
2750	-Chris Hallinan
2751	DS4.COM, Inc.
2752
2753It is essential to remember this, since it has some impact on the C
2754code for the initialization procedures:
2755
2756* Initialized global data (data segment) is read-only. Do not attempt
2757  to write it.
2758
2759* Do not use any unitialized global data (or implicitely initialized
2760  as zero data - BSS segment) at all - this is undefined, initiali-
2761  zation is performed later (when relocationg to RAM).
2762
2763* Stack space is very limited. Avoid big data buffers or things  like
2764  that.
2765
2766Having only the stack as writable memory limits means we cannot use
2767normal global data to share information beween the code. But it
2768turned out that the implementation of U-Boot can be greatly
2769simplified by making a global data structure (gd_t) available to all
2770functions. We could pass a pointer to this data as argument to _all_
2771functions, but this would bloat the code. Instead we use a feature of
2772the GCC compiler (Global Register Variables) to share the data: we
2773place a pointer (gd) to the global data into a register which we
2774reserve for this purpose.
2775
2776When chosing a register for such a purpose we are restricted  by  the
2777relevant  (E)ABI  specifications for the current architecture, and by
2778GCC's implementation.
2779
2780For PowerPC, the following registers have specific use:
2781	R1:	stack pointer
2782	R2:	TOC pointer
2783	R3-R4:	parameter passing and return values
2784	R5-R10:	parameter passing
2785	R13:	small data area pointer
2786	R30:	GOT pointer
2787	R31:	frame pointer
2788
2789	(U-Boot also uses R14 as internal GOT pointer.)
2790
2791    ==> U-Boot will use R29 to hold a pointer to the global data
2792
2793    Note: on PPC, we could use a static initializer (since the
2794    address of the global data structure is known at compile time),
2795    but it turned out that reserving a register results in somewhat
2796    smaller code - although the code savings are not that big (on
2797    average for all boards 752 bytes for the whole U-Boot image,
2798    624 text + 127 data).
2799
2800On ARM, the following registers are used:
2801
2802	R0:	function argument word/integer result
2803	R1-R3:	function argument word
2804	R9:	GOT pointer
2805	R10:	stack limit (used only if stack checking if enabled)
2806	R11:	argument (frame) pointer
2807	R12:	temporary workspace
2808	R13:	stack pointer
2809	R14:	link register
2810	R15:	program counter
2811
2812    ==> U-Boot will use R8 to hold a pointer to the global data
2813
2814
2815
2816Memory Management:
2817------------------
2818
2819U-Boot runs in system state and uses physical addresses, i.e. the
2820MMU is not used either for address mapping nor for memory protection.
2821
2822The available memory is mapped to fixed addresses using the memory
2823controller. In this process, a contiguous block is formed for each
2824memory type (Flash, SDRAM, SRAM), even when it consists of several
2825physical memory banks.
2826
2827U-Boot is installed in the first 128 kB of the first Flash bank (on
2828TQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2829booting and sizing and initializing DRAM, the code relocates itself
2830to the upper end of DRAM. Immediately below the U-Boot code some
2831memory is reserved for use by malloc() [see CFG_MALLOC_LEN
2832configuration setting]. Below that, a structure with global Board
2833Info data is placed, followed by the stack (growing downward).
2834
2835Additionally, some exception handler code is copied to the low 8 kB
2836of DRAM (0x00000000 ... 0x00001FFF).
2837
2838So a typical memory configuration with 16 MB of DRAM could look like
2839this:
2840
2841	0x0000 0000	Exception Vector code
2842	      :
2843	0x0000 1FFF
2844	0x0000 2000	Free for Application Use
2845	      :
2846	      :
2847
2848	      :
2849	      :
2850	0x00FB FF20	Monitor Stack (Growing downward)
2851	0x00FB FFAC	Board Info Data and permanent copy of global data
2852	0x00FC 0000	Malloc Arena
2853	      :
2854	0x00FD FFFF
2855	0x00FE 0000	RAM Copy of Monitor Code
2856	...		eventually: LCD or video framebuffer
2857	...		eventually: pRAM (Protected RAM - unchanged by reset)
2858	0x00FF FFFF	[End of RAM]
2859
2860
2861System Initialization:
2862----------------------
2863
2864In the reset configuration, U-Boot starts at the reset entry point
2865(on most PowerPC systens at address 0x00000100). Because of the reset
2866configuration for CS0# this is a mirror of the onboard Flash memory.
2867To be able to re-map memory U-Boot then jumps to it's link address.
2868To be able to implement the initialization code in C, a (small!)
2869initial stack is set up in the internal Dual Ported RAM (in case CPUs
2870which provide such a feature like MPC8xx or MPC8260), or in a locked
2871part of the data cache. After that, U-Boot initializes the CPU core,
2872the caches and the SIU.
2873
2874Next, all (potentially) available memory banks are mapped using a
2875preliminary mapping. For example, we put them on 512 MB boundaries
2876(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2877on 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2878programmed for SDRAM access. Using the temporary configuration, a
2879simple memory test is run that determines the size of the SDRAM
2880banks.
2881
2882When there is more than one SDRAM bank, and the banks are of
2883different size, the larger is mapped first. For equal size, the first
2884bank (CS2#) is mapped first. The first mapping is always for address
28850x00000000, with any additional banks following immediately to create
2886contiguous memory starting from 0.
2887
2888Then, the monitor installs itself at the upper end of the SDRAM area
2889and allocates memory for use by malloc() and for the global Board
2890Info data; also, the exception vector code is copied to the low RAM
2891pages, and the final stack is set up.
2892
2893Only after this relocation will you have a "normal" C environment;
2894until that you are restricted in several ways, mostly because you are
2895running from ROM, and because the code will have to be relocated to a
2896new address in RAM.
2897
2898
2899U-Boot Porting Guide:
2900----------------------
2901
2902[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
2903list, October 2002]
2904
2905
2906int main (int argc, char *argv[])
2907{
2908	sighandler_t no_more_time;
2909
2910	signal (SIGALRM, no_more_time);
2911	alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2912
2913	if (available_money > available_manpower) {
2914		pay consultant to port U-Boot;
2915		return 0;
2916	}
2917
2918	Download latest U-Boot source;
2919
2920	Subscribe to u-boot-users mailing list;
2921
2922	if (clueless) {
2923		email ("Hi, I am new to U-Boot, how do I get started?");
2924	}
2925
2926	while (learning) {
2927		Read the README file in the top level directory;
2928		Read http://www.denx.de/re/DPLG.html
2929		Read the source, Luke;
2930	}
2931
2932	if (available_money > toLocalCurrency ($2500)) {
2933		Buy a BDI2000;
2934	} else {
2935		Add a lot of aggravation and time;
2936	}
2937
2938	Create your own board support subdirectory;
2939
2940	Create your own board config file;
2941
2942	while (!running) {
2943		do {
2944			Add / modify source code;
2945		} until (compiles);
2946		Debug;
2947		if (clueless)
2948			email ("Hi, I am having problems...");
2949	}
2950	Send patch file to Wolfgang;
2951
2952	return 0;
2953}
2954
2955void no_more_time (int sig)
2956{
2957      hire_a_guru();
2958}
2959
2960
2961
2962Coding Standards:
2963-----------------
2964
2965All contributions to U-Boot should conform to the Linux kernel
2966coding style; see the file "Documentation/CodingStyle" in your Linux
2967kernel source directory.
2968
2969Please note that U-Boot is implemented in C (and to some small parts
2970in Assembler); no C++ is used, so please do not use C++ style
2971comments (//) in your code.
2972
2973Submissions which do not conform to the standards may be returned
2974with a request to reformat the changes.
2975
2976
2977Submitting Patches:
2978-------------------
2979
2980Since the number of patches for U-Boot is growing, we need to
2981establish some rules. Submissions which do not conform to these rules
2982may be rejected, even when they contain important and valuable stuff.
2983
2984
2985When you send a patch, please include the following information with
2986it:
2987
2988* For bug fixes: a description of the bug and how your patch fixes
2989  this bug. Please try to include a way of demonstrating that the
2990  patch actually fixes something.
2991
2992* For new features: a description of the feature and your
2993  implementation.
2994
2995* A CHANGELOG entry as plaintext (separate from the patch)
2996
2997* For major contributions, your entry to the CREDITS file
2998
2999* When you add support for a new board, don't forget to add this
3000  board to the MAKEALL script, too.
3001
3002* If your patch adds new configuration options, don't forget to
3003  document these in the README file.
3004
3005* The patch itself. If you are accessing the CVS repository use "cvs
3006  update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3007  version of diff does not support these options, then get the latest
3008  version of GNU diff.
3009
3010  We accept patches as plain text, MIME attachments or as uuencoded
3011  gzipped text.
3012
3013* If one logical set of modifications affects or creates several
3014  files, all these changes shall be submitted in a SINGLE patch file.
3015
3016* Changesets that contain different, unrelated modifications shall be
3017  submitted as SEPARATE patches, one patch per changeset.
3018
3019
3020Notes:
3021
3022* Before sending the patch, run the MAKEALL script on your patched
3023  source tree and make sure that no errors or warnings are reported
3024  for any of the boards.
3025
3026* Keep your modifications to the necessary minimum: A patch
3027  containing several unrelated changes or arbitrary reformats will be
3028  returned with a request to re-formatting / split it.
3029
3030* If you modify existing code, make sure that your new code does not
3031  add to the memory footprint of the code ;-) Small is beautiful!
3032  When adding new features, these should compile conditionally only
3033  (using #ifdef), and the resulting code with the new feature
3034  disabled must not need more memory than the old code without your
3035  modification.
3036