xref: /openbmc/u-boot/README (revision 72755c7137396fdd8230dfc498294760fa2aaeb4)
1c609719bSwdenk#
2c609719bSwdenk# (C) Copyright 2000 - 2002
3c609719bSwdenk# Wolfgang Denk, DENX Software Engineering, wd@denx.de.
4c609719bSwdenk#
5c609719bSwdenk# See file CREDITS for list of people who contributed to this
6c609719bSwdenk# project.
7c609719bSwdenk#
8c609719bSwdenk# This program is free software; you can redistribute it and/or
9c609719bSwdenk# modify it under the terms of the GNU General Public License as
10c609719bSwdenk# published by the Free Software Foundation; either version 2 of
11c609719bSwdenk# the License, or (at your option) any later version.
12c609719bSwdenk#
13c609719bSwdenk# This program is distributed in the hope that it will be useful,
14c609719bSwdenk# but WITHOUT ANY WARRANTY; without even the implied warranty of
15c609719bSwdenk# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	See the
16c609719bSwdenk# GNU General Public License for more details.
17c609719bSwdenk#
18c609719bSwdenk# You should have received a copy of the GNU General Public License
19c609719bSwdenk# along with this program; if not, write to the Free Software
20c609719bSwdenk# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
21c609719bSwdenk# MA 02111-1307 USA
22c609719bSwdenk#
23c609719bSwdenk
24c609719bSwdenkSummary:
25c609719bSwdenk========
26c609719bSwdenk
2724ee89b9SwdenkThis directory contains the source code for U-Boot, a boot loader for
2824ee89b9SwdenkEmbedded boards based on PowerPC and ARM processors, which can be
2924ee89b9Swdenkinstalled in a boot ROM and used to initialize and test the hardware
3024ee89b9Swdenkor to download and run application code.
31c609719bSwdenk
32c609719bSwdenkThe development of U-Boot is closely related to Linux: some parts of
3324ee89b9Swdenkthe source code originate in the Linux source tree, we have some
3424ee89b9Swdenkheader files in common, and special provision has been made to
35c609719bSwdenksupport booting of Linux images.
36c609719bSwdenk
37c609719bSwdenkSome attention has been paid to make this software easily
38c609719bSwdenkconfigurable and extendable. For instance, all monitor commands are
39c609719bSwdenkimplemented with the same call interface, so that it's very easy to
40c609719bSwdenkadd new commands. Also, instead of permanently adding rarely used
41c609719bSwdenkcode (for instance hardware test utilities) to the monitor, you can
42c609719bSwdenkload and run it dynamically.
43c609719bSwdenk
44c609719bSwdenk
45c609719bSwdenkStatus:
46c609719bSwdenk=======
47c609719bSwdenk
48c609719bSwdenkIn general, all boards for which a configuration option exists in the
49c609719bSwdenkMakefile have been tested to some extent and can be considered
50c609719bSwdenk"working". In fact, many of them are used in production systems.
51c609719bSwdenk
52c609719bSwdenkIn case of problems see the CHANGELOG and CREDITS files to find out
53c609719bSwdenkwho contributed the specific port.
54c609719bSwdenk
55c609719bSwdenk
56c609719bSwdenkWhere to get help:
57c609719bSwdenk==================
58c609719bSwdenk
59c609719bSwdenkIn case you have questions about, problems with or contributions for
60c609719bSwdenkU-Boot you should send a message to the U-Boot mailing list at
61c609719bSwdenk<u-boot-users@lists.sourceforge.net>. There is also an archive of
62c609719bSwdenkprevious traffic on the mailing list - please search the archive
63c609719bSwdenkbefore asking FAQ's. Please see
64c609719bSwdenkhttp://lists.sourceforge.net/lists/listinfo/u-boot-users/
65c609719bSwdenk
66c609719bSwdenk
67c609719bSwdenkWhere we come from:
68c609719bSwdenk===================
69c609719bSwdenk
70c609719bSwdenk- start from 8xxrom sources
7124ee89b9Swdenk- create PPCBoot project (http://sourceforge.net/projects/ppcboot)
72c609719bSwdenk- clean up code
73c609719bSwdenk- make it easier to add custom boards
74c609719bSwdenk- make it possible to add other [PowerPC] CPUs
75c609719bSwdenk- extend functions, especially:
76c609719bSwdenk  * Provide extended interface to Linux boot loader
77c609719bSwdenk  * S-Record download
78c609719bSwdenk  * network boot
79c609719bSwdenk  * PCMCIA / CompactFLash / ATA disk / SCSI ... boot
8024ee89b9Swdenk- create ARMBoot project (http://sourceforge.net/projects/armboot)
81c609719bSwdenk- add other CPU families (starting with ARM)
8224ee89b9Swdenk- create U-Boot project (http://sourceforge.net/projects/u-boot)
8324ee89b9Swdenk
8424ee89b9Swdenk
8524ee89b9SwdenkNames and Spelling:
8624ee89b9Swdenk===================
8724ee89b9Swdenk
8824ee89b9SwdenkThe "official" name of this project is "Das U-Boot". The spelling
8924ee89b9Swdenk"U-Boot" shall be used in all written text (documentation, comments
9024ee89b9Swdenkin source files etc.). Example:
9124ee89b9Swdenk
9224ee89b9Swdenk	This is the README file for the U-Boot project.
9324ee89b9Swdenk
9424ee89b9SwdenkFile names etc. shall be based on the string "u-boot". Examples:
9524ee89b9Swdenk
9624ee89b9Swdenk	include/asm-ppc/u-boot.h
9724ee89b9Swdenk
9824ee89b9Swdenk	#include <asm/u-boot.h>
9924ee89b9Swdenk
10024ee89b9SwdenkVariable names, preprocessor constants etc. shall be either based on
10124ee89b9Swdenkthe string "u_boot" or on "U_BOOT". Example:
10224ee89b9Swdenk
10324ee89b9Swdenk	U_BOOT_VERSION		u_boot_logo
10424ee89b9Swdenk	IH_OS_U_BOOT		u_boot_hush_start
105c609719bSwdenk
106c609719bSwdenk
10793f19cc0SwdenkVersioning:
10893f19cc0Swdenk===========
10993f19cc0Swdenk
11093f19cc0SwdenkU-Boot uses a 3 level version number containing a version, a
11193f19cc0Swdenksub-version, and a patchlevel: "U-Boot-2.34.5" means version "2",
11293f19cc0Swdenksub-version "34", and patchlevel "4".
11393f19cc0Swdenk
11493f19cc0SwdenkThe patchlevel is used to indicate certain stages of development
11593f19cc0Swdenkbetween released versions, i. e. officially released versions of
11693f19cc0SwdenkU-Boot will always have a patchlevel of "0".
11793f19cc0Swdenk
11893f19cc0Swdenk
119c609719bSwdenkDirectory Hierarchy:
120c609719bSwdenk====================
121c609719bSwdenk
122c609719bSwdenk- board		Board dependend files
123c609719bSwdenk- common	Misc architecture independend functions
124c609719bSwdenk- cpu		CPU specific files
125c609719bSwdenk- disk		Code for disk drive partition handling
126c609719bSwdenk- doc		Documentation (don't expect too much)
127c609719bSwdenk- drivers	Common used device drivers
128c609719bSwdenk- dtt		Digital Thermometer and Thermostat drivers
129c609719bSwdenk- examples	Example code for standalone applications, etc.
130c609719bSwdenk- include	Header Files
131c609719bSwdenk- disk		Harddisk interface code
132c609719bSwdenk- net		Networking code
133c609719bSwdenk- ppc		Files generic to PowerPC architecture
134c609719bSwdenk- post		Power On Self Test
135c609719bSwdenk- post/arch		Symlink to architecture specific Power On Self Test
136c609719bSwdenk- post/arch-ppc		PowerPC architecture specific Power On Self Test
137c609719bSwdenk- post/cpu/mpc8260	MPC8260 CPU specific Power On Self Test
138c609719bSwdenk- post/cpu/mpc8xx	MPC8xx CPU specific Power On Self Test
139c609719bSwdenk- rtc		Real Time Clock drivers
140c609719bSwdenk- tools		Tools to build S-Record or U-Boot images, etc.
141c609719bSwdenk
142c609719bSwdenk- cpu/74xx_7xx	Files specific to Motorola MPC74xx and 7xx CPUs
1430db5bca8Swdenk- cpu/mpc5xx	Files specific to Motorola MPC5xx  CPUs
144c609719bSwdenk- cpu/mpc8xx	Files specific to Motorola MPC8xx  CPUs
145c609719bSwdenk- cpu/mpc824x	Files specific to Motorola MPC824x CPUs
146c609719bSwdenk- cpu/mpc8260	Files specific to Motorola MPC8260 CPU
147c609719bSwdenk- cpu/ppc4xx	Files specific to IBM	   4xx	   CPUs
148c609719bSwdenk
1493bac3513Swdenk- board/LEOX/   Files specific to boards manufactured by The LEOX team
1503bac3513Swdenk- board/LEOX/elpt860	Files specific to ELPT860 boards
151c609719bSwdenk- board/RPXClassic
152c609719bSwdenk		Files specific to RPXClassic boards
153c609719bSwdenk- board/RPXlite	Files specific to RPXlite    boards
1542abbe075Swdenk- board/at91rm9200dk Files specific to AT91RM9200DK boards
155c609719bSwdenk- board/c2mon	Files specific to c2mon	     boards
1560db5bca8Swdenk- board/cmi	Files specific to cmi        boards
157c609719bSwdenk- board/cogent	Files specific to Cogent     boards
158c609719bSwdenk		(need further configuration)
159c609719bSwdenk		Files specific to CPCIISER4  boards
160c609719bSwdenk- board/cpu86	Files specific to CPU86      boards
161c609719bSwdenk- board/cray/	Files specific to boards manufactured by Cray
162c609719bSwdenk- board/cray/L1		Files specific to L1         boards
163c609719bSwdenk- board/cu824	Files specific to CU824	     boards
164c609719bSwdenk- board/ebony   Files specific to IBM Ebony board
165c609719bSwdenk- board/eric	Files specific to ERIC	     boards
166c609719bSwdenk- board/esd/	Files specific to boards manufactured by ESD
167c609719bSwdenk- board/esd/adciop	Files specific to ADCIOP     boards
168c609719bSwdenk- board/esd/ar405	Files specific to AR405	     boards
169c609719bSwdenk- board/esd/canbt	Files specific to CANBT	     boards
170c609719bSwdenk- board/esd/cpci405	Files specific to CPCI405    boards
171c609719bSwdenk- board/esd/cpciiser4	Files specific to CPCIISER4  boards
172c609719bSwdenk- board/esd/common	Common files for ESD boards
173c609719bSwdenk- board/esd/dasa_sim	Files specific to DASA_SIM   boards
174c609719bSwdenk- board/esd/du405	Files specific to DU405      boards
175c609719bSwdenk- board/esd/ocrtc	Files specific to OCRTC      boards
176c609719bSwdenk- board/esd/pci405	Files specific to PCI405     boards
177c609719bSwdenk- board/esteem192e
178c609719bSwdenk		Files specific to ESTEEM192E boards
179c609719bSwdenk- board/etx094	Files specific to ETX_094    boards
180c609719bSwdenk- board/evb64260
181c609719bSwdenk		Files specific to EVB64260   boards
182c609719bSwdenk- board/fads	Files specific to FADS	     boards
183c609719bSwdenk- board/flagadm Files specific to FLAGADM    boards
1847aa78614Swdenk- board/gen860t Files specific to GEN860T and GEN860T_SC    boards
185c609719bSwdenk- board/genietv Files specific to GENIETV    boards
186c609719bSwdenk- board/gth	Files specific to GTH	     boards
187c609719bSwdenk- board/hermes	Files specific to HERMES     boards
188c609719bSwdenk- board/hymod	Files specific to HYMOD	     boards
189c609719bSwdenk- board/icu862	Files specific to ICU862     boards
190c609719bSwdenk- board/ip860	Files specific to IP860	     boards
191c609719bSwdenk- board/iphase4539
192c609719bSwdenk		Files specific to Interphase4539 boards
193c609719bSwdenk- board/ivm	Files specific to IVMS8/IVML24 boards
194c609719bSwdenk- board/lantec	Files specific to LANTEC     boards
195c609719bSwdenk- board/lwmon	Files specific to LWMON	     boards
196c609719bSwdenk- board/mbx8xx	Files specific to MBX	     boards
197c609719bSwdenk- board/mpc8260ads
198c609719bSwdenk		Files specific to MMPC8260ADS boards
199c609719bSwdenk- board/mpl/	Files specific to boards manufactured by MPL
200c609719bSwdenk- board/mpl/common	Common files for MPL boards
201c609719bSwdenk- board/mpl/pip405	Files specific to PIP405     boards
202c609719bSwdenk- board/mpl/mip405	Files specific to MIP405     boards
203c609719bSwdenk- board/musenki	Files specific to MUSEKNI    boards
204c609719bSwdenk- board/mvs1	Files specific to MVS1       boards
205c609719bSwdenk- board/nx823   Files specific to NX823      boards
206c609719bSwdenk- board/oxc	Files specific to OXC        boards
207c609719bSwdenk- board/pcippc2	Files specific to PCIPPC2/PCIPPC6 boards
208c609719bSwdenk- board/pm826	Files specific to PM826      boards
209c609719bSwdenk- board/ppmc8260
210c609719bSwdenk		Files specific to PPMC8260   boards
211c609719bSwdenk- board/rpxsuper
212c609719bSwdenk		Files specific to RPXsuper   boards
213c609719bSwdenk- board/rsdproto
214c609719bSwdenk		Files specific to RSDproto   boards
215c609719bSwdenk- board/sandpoint
216c609719bSwdenk		Files specific to Sandpoint  boards
217c609719bSwdenk- board/sbc8260	Files specific to SBC8260    boards
218c609719bSwdenk- board/sacsng	Files specific to SACSng     boards
219c609719bSwdenk- board/siemens Files specific to boards manufactured by Siemens AG
220c609719bSwdenk- board/siemens/CCM	Files specific to CCM	     boards
221c609719bSwdenk- board/siemens/IAD210	Files specific to IAD210     boards
222c609719bSwdenk- board/siemens/SCM	Files specific to SCM        boards
223c609719bSwdenk- board/siemens/pcu_e	Files specific to PCU_E	     boards
224c609719bSwdenk- board/sixnet	Files specific to SIXNET     boards
225c609719bSwdenk- board/spd8xx	Files specific to SPD8xxTS   boards
226c609719bSwdenk- board/tqm8260 Files specific to TQM8260    boards
227c609719bSwdenk- board/tqm8xx	Files specific to TQM8xxL    boards
228c609719bSwdenk- board/w7o	Files specific to W7O        boards
229c609719bSwdenk- board/walnut405
230c609719bSwdenk		Files specific to Walnut405  boards
231c609719bSwdenk- board/westel/	Files specific to boards manufactured by Westel Wireless
232c609719bSwdenk- board/westel/amx860	Files specific to AMX860     boards
233c609719bSwdenk- board/utx8245	Files specific to UTX8245   boards
234c609719bSwdenk
235c609719bSwdenkSoftware Configuration:
236c609719bSwdenk=======================
237c609719bSwdenk
238c609719bSwdenkConfiguration is usually done using C preprocessor defines; the
239c609719bSwdenkrationale behind that is to avoid dead code whenever possible.
240c609719bSwdenk
241c609719bSwdenkThere are two classes of configuration variables:
242c609719bSwdenk
243c609719bSwdenk* Configuration _OPTIONS_:
244c609719bSwdenk  These are selectable by the user and have names beginning with
245c609719bSwdenk  "CONFIG_".
246c609719bSwdenk
247c609719bSwdenk* Configuration _SETTINGS_:
248c609719bSwdenk  These depend on the hardware etc. and should not be meddled with if
249c609719bSwdenk  you don't know what you're doing; they have names beginning with
250c609719bSwdenk  "CFG_".
251c609719bSwdenk
252c609719bSwdenkLater we will add a configuration tool - probably similar to or even
253c609719bSwdenkidentical to what's used for the Linux kernel. Right now, we have to
254c609719bSwdenkdo the configuration by hand, which means creating some symbolic
255c609719bSwdenklinks and editing some configuration files. We use the TQM8xxL boards
256c609719bSwdenkas an example here.
257c609719bSwdenk
258c609719bSwdenk
259c609719bSwdenkSelection of Processor Architecture and Board Type:
260c609719bSwdenk---------------------------------------------------
261c609719bSwdenk
262c609719bSwdenkFor all supported boards there are ready-to-use default
263c609719bSwdenkconfigurations available; just type "make <board_name>_config".
264c609719bSwdenk
265c609719bSwdenkExample: For a TQM823L module type:
266c609719bSwdenk
267c609719bSwdenk	cd u-boot
268c609719bSwdenk	make TQM823L_config
269c609719bSwdenk
270c609719bSwdenkFor the Cogent platform, you need to specify the cpu type as well;
271c609719bSwdenke.g. "make cogent_mpc8xx_config". And also configure the cogent
272c609719bSwdenkdirectory according to the instructions in cogent/README.
273c609719bSwdenk
274c609719bSwdenk
275c609719bSwdenkConfiguration Options:
276c609719bSwdenk----------------------
277c609719bSwdenk
278c609719bSwdenkConfiguration depends on the combination of board and CPU type; all
279c609719bSwdenksuch information is kept in a configuration file
280c609719bSwdenk"include/configs/<board_name>.h".
281c609719bSwdenk
282c609719bSwdenkExample: For a TQM823L module, all configuration settings are in
283c609719bSwdenk"include/configs/TQM823L.h".
284c609719bSwdenk
285c609719bSwdenk
2867f6c2cbcSwdenkMany of the options are named exactly as the corresponding Linux
2877f6c2cbcSwdenkkernel configuration options. The intention is to make it easier to
2887f6c2cbcSwdenkbuild a config tool - later.
2897f6c2cbcSwdenk
2907f6c2cbcSwdenk
291c609719bSwdenkThe following options need to be configured:
292c609719bSwdenk
293c609719bSwdenk- CPU Type:	Define exactly one of
294c609719bSwdenk
295c609719bSwdenk		PowerPC based CPUs:
296c609719bSwdenk		-------------------
297c609719bSwdenk		CONFIG_MPC823,	CONFIG_MPC850,	CONFIG_MPC855,	CONFIG_MPC860
2980db5bca8Swdenk	or	CONFIG_MPC5xx
299c609719bSwdenk	or	CONFIG_MPC824X, CONFIG_MPC8260
300c609719bSwdenk	or	CONFIG_IOP480
301c609719bSwdenk	or	CONFIG_405GP
302c609719bSwdenk	or	CONFIG_440
303c609719bSwdenk	or	CONFIG_MPC74xx
304*72755c71Swdenk	or	CONFIG_750FX
305c609719bSwdenk
306c609719bSwdenk		ARM based CPUs:
307c609719bSwdenk		---------------
308c609719bSwdenk		CONFIG_SA1110
309c609719bSwdenk		CONFIG_ARM7
310c609719bSwdenk		CONFIG_PXA250
311c609719bSwdenk
312c609719bSwdenk
313c609719bSwdenk- Board Type:	Define exactly one of
314c609719bSwdenk
315c609719bSwdenk		PowerPC based boards:
316c609719bSwdenk		---------------------
317c609719bSwdenk
318c609719bSwdenk		CONFIG_ADCIOP,     CONFIG_ICU862      CONFIG_RPXsuper,
319c609719bSwdenk		CONFIG_ADS860,     CONFIG_IP860,      CONFIG_SM850,
320c609719bSwdenk		CONFIG_AMX860,     CONFIG_IPHASE4539, CONFIG_SPD823TS,
321c609719bSwdenk		CONFIG_AR405,      CONFIG_IVML24,     CONFIG_SXNI855T,
322c609719bSwdenk		CONFIG_BAB7xx,     CONFIG_IVML24_128, CONFIG_Sandpoint8240,
323c609719bSwdenk		CONFIG_CANBT,      CONFIG_IVML24_256, CONFIG_Sandpoint8245,
324c609719bSwdenk		CONFIG_CCM,        CONFIG_IVMS8,      CONFIG_TQM823L,
325c609719bSwdenk		CONFIG_CPCI405,    CONFIG_IVMS8_128,  CONFIG_TQM850L,
326c609719bSwdenk		CONFIG_CPCI4052,   CONFIG_IVMS8_256,  CONFIG_TQM855L,
327c609719bSwdenk		CONFIG_CPCIISER4,  CONFIG_LANTEC,     CONFIG_TQM860L,
328c609719bSwdenk		CONFIG_CPU86,      CONFIG_MBX,        CONFIG_TQM8260,
329c609719bSwdenk		CONFIG_CRAYL1,     CONFIG_MBX860T,    CONFIG_TTTech,
330c609719bSwdenk		CONFIG_CU824,      CONFIG_MHPC,       CONFIG_UTX8245,
331c609719bSwdenk		CONFIG_DASA_SIM,   CONFIG_MIP405,     CONFIG_W7OLMC,
332c609719bSwdenk		CONFIG_DU405,      CONFIG_MOUSSE,     CONFIG_W7OLMG,
333c609719bSwdenk		CONFIG_ELPPC,      CONFIG_MPC8260ADS, CONFIG_WALNUT405,
334c609719bSwdenk		CONFIG_ERIC,       CONFIG_MUSENKI,    CONFIG_ZUMA,
335c609719bSwdenk		CONFIG_ESTEEM192E, CONFIG_MVS1,       CONFIG_c2mon,
336c609719bSwdenk		CONFIG_ETX094,     CONFIG_NX823,      CONFIG_cogent_mpc8260,
337c609719bSwdenk		CONFIG_EVB64260,   CONFIG_OCRTC,      CONFIG_cogent_mpc8xx,
338c609719bSwdenk		CONFIG_FADS823,    CONFIG_ORSG,       CONFIG_ep8260,
339c609719bSwdenk		CONFIG_FADS850SAR, CONFIG_OXC,        CONFIG_gw8260,
340c609719bSwdenk		CONFIG_FADS860T,   CONFIG_PCI405,     CONFIG_hermes,
341c609719bSwdenk		CONFIG_FLAGADM,    CONFIG_PCIPPC2,    CONFIG_hymod,
342c609719bSwdenk		CONFIG_FPS850L,    CONFIG_PCIPPC6,    CONFIG_lwmon,
343c609719bSwdenk		CONFIG_GEN860T,    CONFIG_PIP405,     CONFIG_pcu_e,
344c609719bSwdenk		CONFIG_GENIETV,    CONFIG_PM826,      CONFIG_ppmc8260,
345c609719bSwdenk		CONFIG_GTH,        CONFIG_RPXClassic, CONFIG_rsdproto,
346c609719bSwdenk		CONFIG_IAD210,     CONFIG_RPXlite,    CONFIG_sbc8260,
347608c9146Swdenk		CONFIG_EBONY,      CONFIG_sacsng,     CONFIG_FPS860L,
3487f70e853Swdenk		CONFIG_V37,        CONFIG_ELPT860,    CONFIG_CMI,
349682011ffSwdenk		CONFIG_NETVIA,     CONFIG_RBC823
350c609719bSwdenk
351c609719bSwdenk		ARM based boards:
352c609719bSwdenk		-----------------
353c609719bSwdenk
354c609719bSwdenk		CONFIG_HHP_CRADLE,  CONFIG_DNP1110,    CONFIG_EP7312,
355c609719bSwdenk		CONFIG_IMPA7,       CONFIG_LART,       CONFIG_LUBBOCK,
356c609719bSwdenk		CONFIG_SHANNON,     CONFIG_SMDK2400,   CONFIG_SMDK2410,
3572abbe075Swdenk		CONFIG_TRAB,	    CONFIG_AT91RM9200DK
358c609719bSwdenk
359c609719bSwdenk
360c609719bSwdenk- CPU Module Type: (if CONFIG_COGENT is defined)
361c609719bSwdenk		Define exactly one of
362c609719bSwdenk		CONFIG_CMA286_60_OLD
363c609719bSwdenk--- FIXME --- not tested yet:
364c609719bSwdenk		CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
365c609719bSwdenk		CONFIG_CMA287_23, CONFIG_CMA287_50
366c609719bSwdenk
367c609719bSwdenk- Motherboard Type: (if CONFIG_COGENT is defined)
368c609719bSwdenk		Define exactly one of
369c609719bSwdenk		CONFIG_CMA101, CONFIG_CMA102
370c609719bSwdenk
371c609719bSwdenk- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
372c609719bSwdenk		Define one or more of
373c609719bSwdenk		CONFIG_CMA302
374c609719bSwdenk
375c609719bSwdenk- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
376c609719bSwdenk		Define one or more of
377c609719bSwdenk		CONFIG_LCD_HEARTBEAT	- update a character position on
378c609719bSwdenk					  the lcd display every second with
379c609719bSwdenk					  a "rotator" |\-/|\-/
380c609719bSwdenk
381c609719bSwdenk- MPC824X Family Member (if CONFIG_MPC824X is defined)
382c609719bSwdenk	Define exactly one of
383c609719bSwdenk	CONFIG_MPC8240, CONFIG_MPC8245
384c609719bSwdenk
385c609719bSwdenk- 8xx CPU Options: (if using an 8xx cpu)
386c609719bSwdenk		Define one or more of
387c609719bSwdenk		CONFIG_8xx_GCLK_FREQ	- if get_gclk_freq() can not work e.g.
388c609719bSwdenk					  no 32KHz reference PIT/RTC clock
389c609719bSwdenk
390c609719bSwdenk- Clock Interface:
391c609719bSwdenk		CONFIG_CLOCKS_IN_MHZ
392c609719bSwdenk
393c609719bSwdenk		U-Boot stores all clock information in Hz
394c609719bSwdenk		internally. For binary compatibility with older Linux
395c609719bSwdenk		kernels (which expect the clocks passed in the
396c609719bSwdenk		bd_info data to be in MHz) the environment variable
397c609719bSwdenk		"clocks_in_mhz" can be defined so that U-Boot
398c609719bSwdenk		converts clock data to MHZ before passing it to the
399c609719bSwdenk		Linux kernel.
400c609719bSwdenk
401c609719bSwdenk		When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
402c609719bSwdenk		"clocks_in_mhz=1" is  automatically  included  in  the
403c609719bSwdenk		default environment.
404c609719bSwdenk
405c609719bSwdenk- Console Interface:
406c609719bSwdenk		Depending on board, define exactly one serial port
407c609719bSwdenk		(like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
408c609719bSwdenk		CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
409c609719bSwdenk		console by defining CONFIG_8xx_CONS_NONE
410c609719bSwdenk
411c609719bSwdenk		Note: if CONFIG_8xx_CONS_NONE is defined, the serial
412c609719bSwdenk		port routines must be defined elsewhere
413c609719bSwdenk		(i.e. serial_init(), serial_getc(), ...)
414c609719bSwdenk
415c609719bSwdenk		CONFIG_CFB_CONSOLE
416c609719bSwdenk		Enables console device for a color framebuffer. Needs following
417c609719bSwdenk		defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
418c609719bSwdenk			VIDEO_FB_LITTLE_ENDIAN	graphic memory organisation
419c609719bSwdenk						(default big endian)
420c609719bSwdenk			VIDEO_HW_RECTFILL	graphic chip supports
421c609719bSwdenk						rectangle fill
422c609719bSwdenk						(cf. smiLynxEM)
423c609719bSwdenk			VIDEO_HW_BITBLT		graphic chip supports
424c609719bSwdenk						bit-blit (cf. smiLynxEM)
425c609719bSwdenk			VIDEO_VISIBLE_COLS	visible pixel columns
426c609719bSwdenk						(cols=pitch)
427c609719bSwdenk			VIDEO_VISIBLE_ROWS      visible pixel rows
428c609719bSwdenk			VIDEO_PIXEL_SIZE        bytes per pixel
429c609719bSwdenk			VIDEO_DATA_FORMAT	graphic data format
430c609719bSwdenk						(0-5, cf. cfb_console.c)
431c609719bSwdenk			VIDEO_FB_ADRS           framebuffer address
432c609719bSwdenk			VIDEO_KBD_INIT_FCT	keyboard int fct
433c609719bSwdenk						(i.e. i8042_kbd_init())
434c609719bSwdenk			VIDEO_TSTC_FCT		test char fct
435c609719bSwdenk						(i.e. i8042_tstc)
436c609719bSwdenk			VIDEO_GETC_FCT		get char fct
437c609719bSwdenk						(i.e. i8042_getc)
438c609719bSwdenk			CONFIG_CONSOLE_CURSOR	cursor drawing on/off
439c609719bSwdenk						(requires blink timer
440c609719bSwdenk						cf. i8042.c)
441c609719bSwdenk			CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
442c609719bSwdenk			CONFIG_CONSOLE_TIME	display time/date info in
443c609719bSwdenk						upper right corner
444c609719bSwdenk						(requires CFG_CMD_DATE)
445c609719bSwdenk			CONFIG_VIDEO_LOGO	display Linux logo in
446c609719bSwdenk						upper left corner
447a6c7ad2fSwdenk			CONFIG_VIDEO_BMP_LOGO	use bmp_logo.h instead of
448a6c7ad2fSwdenk						linux_logo.h for logo.
449a6c7ad2fSwdenk						Requires CONFIG_VIDEO_LOGO
450c609719bSwdenk			CONFIG_CONSOLE_EXTRA_INFO
451c609719bSwdenk						addional board info beside
452c609719bSwdenk						the logo
453c609719bSwdenk
454c609719bSwdenk		When CONFIG_CFB_CONSOLE is defined, video console is
455c609719bSwdenk		default i/o. Serial console can be forced with
456c609719bSwdenk		environment 'console=serial'.
457c609719bSwdenk
458c609719bSwdenk- Console Baudrate:
459c609719bSwdenk		CONFIG_BAUDRATE - in bps
460c609719bSwdenk		Select one of the baudrates listed in
461c609719bSwdenk		CFG_BAUDRATE_TABLE, see below.
462c609719bSwdenk
463c609719bSwdenk- Interrupt driven serial port input:
464c609719bSwdenk		CONFIG_SERIAL_SOFTWARE_FIFO
465c609719bSwdenk
466c609719bSwdenk		PPC405GP only.
467c609719bSwdenk		Use an interrupt handler for receiving data on the
468c609719bSwdenk		serial port. It also enables using hardware handshake
469c609719bSwdenk		(RTS/CTS) and UART's built-in FIFO. Set the number of
470c609719bSwdenk		bytes the interrupt driven input buffer should have.
471c609719bSwdenk
472c609719bSwdenk		Set to 0 to disable this feature (this is the default).
473c609719bSwdenk		This will also disable hardware handshake.
474c609719bSwdenk
4751d49b1f3Sstroese- Console UART Number:
4761d49b1f3Sstroese		CONFIG_UART1_CONSOLE
4771d49b1f3Sstroese
4781d49b1f3Sstroese		IBM PPC4xx only.
4791d49b1f3Sstroese		If defined internal UART1 (and not UART0) is used
4801d49b1f3Sstroese		as default U-Boot console.
4811d49b1f3Sstroese
482c609719bSwdenk- Boot Delay:	CONFIG_BOOTDELAY - in seconds
483c609719bSwdenk		Delay before automatically booting the default image;
484c609719bSwdenk		set to -1 to disable autoboot.
485c609719bSwdenk
486c609719bSwdenk		See doc/README.autoboot for these options that
487c609719bSwdenk		work with CONFIG_BOOTDELAY. None are required.
488c609719bSwdenk		CONFIG_BOOT_RETRY_TIME
489c609719bSwdenk		CONFIG_BOOT_RETRY_MIN
490c609719bSwdenk		CONFIG_AUTOBOOT_KEYED
491c609719bSwdenk		CONFIG_AUTOBOOT_PROMPT
492c609719bSwdenk		CONFIG_AUTOBOOT_DELAY_STR
493c609719bSwdenk		CONFIG_AUTOBOOT_STOP_STR
494c609719bSwdenk		CONFIG_AUTOBOOT_DELAY_STR2
495c609719bSwdenk		CONFIG_AUTOBOOT_STOP_STR2
496c609719bSwdenk		CONFIG_ZERO_BOOTDELAY_CHECK
497c609719bSwdenk		CONFIG_RESET_TO_RETRY
498c609719bSwdenk
499c609719bSwdenk- Autoboot Command:
500c609719bSwdenk		CONFIG_BOOTCOMMAND
501c609719bSwdenk		Only needed when CONFIG_BOOTDELAY is enabled;
502c609719bSwdenk		define a command string that is automatically executed
503c609719bSwdenk		when no character is read on the console interface
504c609719bSwdenk		within "Boot Delay" after reset.
505c609719bSwdenk
506c609719bSwdenk		CONFIG_BOOTARGS
507c609719bSwdenk		This can be used to pass arguments to the bootm
508c609719bSwdenk		command. The value of CONFIG_BOOTARGS goes into the
509c609719bSwdenk		environment value "bootargs".
510c609719bSwdenk
511c609719bSwdenk		CONFIG_RAMBOOT and CONFIG_NFSBOOT
512c609719bSwdenk		The value of these goes into the environment as
513c609719bSwdenk		"ramboot" and "nfsboot" respectively, and can be used
514c609719bSwdenk		as a convenience, when switching between booting from
515c609719bSwdenk		ram and nfs.
516c609719bSwdenk
517c609719bSwdenk- Pre-Boot Commands:
518c609719bSwdenk		CONFIG_PREBOOT
519c609719bSwdenk
520c609719bSwdenk		When this option is #defined, the existence of the
521c609719bSwdenk		environment variable "preboot" will be checked
522c609719bSwdenk		immediately before starting the CONFIG_BOOTDELAY
523c609719bSwdenk		countdown and/or running the auto-boot command resp.
524c609719bSwdenk		entering interactive mode.
525c609719bSwdenk
526c609719bSwdenk		This feature is especially useful when "preboot" is
527c609719bSwdenk		automatically generated or modified. For an example
528c609719bSwdenk		see the LWMON board specific code: here "preboot" is
529c609719bSwdenk		modified when the user holds down a certain
530c609719bSwdenk		combination of keys on the (special) keyboard when
531c609719bSwdenk		booting the systems
532c609719bSwdenk
533c609719bSwdenk- Serial Download Echo Mode:
534c609719bSwdenk		CONFIG_LOADS_ECHO
535c609719bSwdenk		If defined to 1, all characters received during a
536c609719bSwdenk		serial download (using the "loads" command) are
537c609719bSwdenk		echoed back. This might be needed by some terminal
538c609719bSwdenk		emulations (like "cu"), but may as well just take
539c609719bSwdenk		time on others. This setting #define's the initial
540c609719bSwdenk		value of the "loads_echo" environment variable.
541c609719bSwdenk
542c609719bSwdenk- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
543c609719bSwdenk		CONFIG_KGDB_BAUDRATE
544c609719bSwdenk		Select one of the baudrates listed in
545c609719bSwdenk		CFG_BAUDRATE_TABLE, see below.
546c609719bSwdenk
547c609719bSwdenk- Monitor Functions:
548c609719bSwdenk		CONFIG_COMMANDS
549c609719bSwdenk		Most monitor functions can be selected (or
550c609719bSwdenk		de-selected) by adjusting the definition of
551c609719bSwdenk		CONFIG_COMMANDS; to select individual functions,
552c609719bSwdenk		#define CONFIG_COMMANDS by "OR"ing any of the
553c609719bSwdenk		following values:
554c609719bSwdenk
555c609719bSwdenk		#define enables commands:
556c609719bSwdenk		-------------------------
557c609719bSwdenk		CFG_CMD_ASKENV	* ask for env variable
558c609719bSwdenk		CFG_CMD_BDI	  bdinfo
559c609719bSwdenk		CFG_CMD_BEDBUG	  Include BedBug Debugger
560c609719bSwdenk		CFG_CMD_BOOTD	  bootd
561c609719bSwdenk		CFG_CMD_CACHE	  icache, dcache
562c609719bSwdenk		CFG_CMD_CONSOLE	  coninfo
563c609719bSwdenk		CFG_CMD_DATE	* support for RTC, date/time...
564c609719bSwdenk		CFG_CMD_DHCP	  DHCP support
565c609719bSwdenk		CFG_CMD_ECHO	* echo arguments
566c609719bSwdenk		CFG_CMD_EEPROM	* EEPROM read/write support
567c609719bSwdenk		CFG_CMD_ELF	  bootelf, bootvx
568c609719bSwdenk		CFG_CMD_ENV	  saveenv
569c609719bSwdenk		CFG_CMD_FDC	* Floppy Disk Support
57071f95118Swdenk		CFG_CMD_FAT	  FAT partition support
5712262cfeeSwdenk		CFG_CMD_FDOS	* Dos diskette Support
572c609719bSwdenk		CFG_CMD_FLASH	  flinfo, erase, protect
573c609719bSwdenk		CFG_CMD_FPGA	  FPGA device initialization support
574c609719bSwdenk		CFG_CMD_I2C	* I2C serial bus support
575c609719bSwdenk		CFG_CMD_IDE	* IDE harddisk support
576c609719bSwdenk		CFG_CMD_IMI	  iminfo
577c609719bSwdenk		CFG_CMD_IMMAP	* IMMR dump support
578c609719bSwdenk		CFG_CMD_IRQ	* irqinfo
579c609719bSwdenk		CFG_CMD_KGDB	* kgdb
580c609719bSwdenk		CFG_CMD_LOADB	  loadb
581c609719bSwdenk		CFG_CMD_LOADS	  loads
582c609719bSwdenk		CFG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base,
583c609719bSwdenk				  loop, mtest
58471f95118Swdenk		CFG_CMD_MMC	  MMC memory mapped support
585c609719bSwdenk		CFG_CMD_MII	  MII utility commands
586c609719bSwdenk		CFG_CMD_NET	  bootp, tftpboot, rarpboot
587c609719bSwdenk		CFG_CMD_PCI	* pciinfo
588c609719bSwdenk		CFG_CMD_PCMCIA	* PCMCIA support
589c609719bSwdenk		CFG_CMD_REGINFO * Register dump
590c609719bSwdenk		CFG_CMD_RUN	  run command in env variable
591c609719bSwdenk		CFG_CMD_SCSI	* SCSI Support
592c609719bSwdenk		CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
593c609719bSwdenk		CFG_CMD_SPI	* SPI serial bus support
594c609719bSwdenk		CFG_CMD_USB	* USB support
595c609719bSwdenk		CFG_CMD_BSP	* Board SPecific functions
596c609719bSwdenk		-----------------------------------------------
597c609719bSwdenk		CFG_CMD_ALL	all
598c609719bSwdenk
599c609719bSwdenk		CFG_CMD_DFL	Default configuration; at the moment
600c609719bSwdenk				this is includes all commands, except
601c609719bSwdenk				the ones marked with "*" in the list
602c609719bSwdenk				above.
603c609719bSwdenk
604c609719bSwdenk		If you don't define CONFIG_COMMANDS it defaults to
605c609719bSwdenk		CFG_CMD_DFL in include/cmd_confdefs.h. A board can
606c609719bSwdenk		override the default settings in the respective
607c609719bSwdenk		include file.
608c609719bSwdenk
609c609719bSwdenk		EXAMPLE: If you want all functions except of network
610c609719bSwdenk		support you can write:
611c609719bSwdenk
612c609719bSwdenk		#define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
613c609719bSwdenk
614c609719bSwdenk
615c609719bSwdenk	Note:	Don't enable the "icache" and "dcache" commands
616c609719bSwdenk		(configuration option CFG_CMD_CACHE) unless you know
617c609719bSwdenk		what you (and your U-Boot users) are doing. Data
618c609719bSwdenk		cache cannot be enabled on systems like the 8xx or
619c609719bSwdenk		8260 (where accesses to the IMMR region must be
620c609719bSwdenk		uncached), and it cannot be disabled on all other
621c609719bSwdenk		systems where we (mis-) use the data cache to hold an
622c609719bSwdenk		initial stack and some data.
623c609719bSwdenk
624c609719bSwdenk
625c609719bSwdenk		XXX - this list needs to get updated!
626c609719bSwdenk
627c609719bSwdenk- Watchdog:
628c609719bSwdenk		CONFIG_WATCHDOG
629c609719bSwdenk		If this variable is defined, it enables watchdog
630c609719bSwdenk		support. There must support in the platform specific
631c609719bSwdenk		code for a watchdog. For the 8xx and 8260 CPUs, the
632c609719bSwdenk		SIU Watchdog feature is enabled in the SYPCR
633c609719bSwdenk		register.
634c609719bSwdenk
635c1551ea8Sstroese- U-Boot Version:
636c1551ea8Sstroese		CONFIG_VERSION_VARIABLE
637c1551ea8Sstroese		If this variable is defined, an environment variable
638c1551ea8Sstroese		named "ver" is created by U-Boot showing the U-Boot
639c1551ea8Sstroese		version as printed by the "version" command.
640c1551ea8Sstroese		This variable is readonly.
641c1551ea8Sstroese
642c609719bSwdenk- Real-Time Clock:
643c609719bSwdenk
644c609719bSwdenk		When CFG_CMD_DATE is selected, the type of the RTC
645c609719bSwdenk		has to be selected, too. Define exactly one of the
646c609719bSwdenk		following options:
647c609719bSwdenk
648c609719bSwdenk		CONFIG_RTC_MPC8xx	- use internal RTC of MPC8xx
649c609719bSwdenk		CONFIG_RTC_PCF8563	- use Philips PCF8563 RTC
650c609719bSwdenk		CONFIG_RTC_MC146818	- use MC146818 RTC
6511cb8e980Swdenk		CONFIG_RTC_DS1307	- use Maxim, Inc. DS1307 RTC
652c609719bSwdenk		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC
6537f70e853Swdenk		CONFIG_RTC_DS1338	- use Maxim, Inc. DS1338 RTC
6543bac3513Swdenk		CONFIG_RTC_DS164x	- use Dallas DS164x RTC
655c609719bSwdenk
656c609719bSwdenk- Timestamp Support:
657c609719bSwdenk
658c609719bSwdenk		When CONFIG_TIMESTAMP is selected, the timestamp
659c609719bSwdenk		(date and time) of an image is printed by image
660c609719bSwdenk		commands like bootm or iminfo. This option is
661c609719bSwdenk		automatically enabled when you select CFG_CMD_DATE .
662c609719bSwdenk
663c609719bSwdenk- Partition Support:
664c609719bSwdenk		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
665c609719bSwdenk		and/or CONFIG_ISO_PARTITION
666c609719bSwdenk
667c609719bSwdenk		If IDE or SCSI support	is  enabled  (CFG_CMD_IDE  or
668c609719bSwdenk		CFG_CMD_SCSI) you must configure support for at least
669c609719bSwdenk		one partition type as well.
670c609719bSwdenk
671c609719bSwdenk- IDE Reset method:
672c609719bSwdenk		CONFIG_IDE_RESET_ROUTINE
673c609719bSwdenk
674c609719bSwdenk		Set this to define that instead of a reset Pin, the
675c609719bSwdenk		routine ide_set_reset(int idereset) will be used.
676c609719bSwdenk
677c609719bSwdenk- ATAPI Support:
678c609719bSwdenk		CONFIG_ATAPI
679c609719bSwdenk
680c609719bSwdenk		Set this to enable ATAPI support.
681c609719bSwdenk
682c609719bSwdenk- SCSI Support:
683c609719bSwdenk		At the moment only there is only support for the
684c609719bSwdenk		SYM53C8XX SCSI controller; define
685c609719bSwdenk		CONFIG_SCSI_SYM53C8XX to enable it.
686c609719bSwdenk
687c609719bSwdenk		CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
688c609719bSwdenk		CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
689c609719bSwdenk		CFG_SCSI_MAX_LUN] can be adjusted to define the
690c609719bSwdenk		maximum numbers of LUNs, SCSI ID's and target
691c609719bSwdenk		devices.
692c609719bSwdenk		CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
693c609719bSwdenk
694c609719bSwdenk- NETWORK Support (PCI):
695682011ffSwdenk		CONFIG_E1000
696682011ffSwdenk		Support for Intel 8254x gigabit chips.
697682011ffSwdenk
698c609719bSwdenk		CONFIG_EEPRO100
699c609719bSwdenk		Support for Intel 82557/82559/82559ER chips.
700c609719bSwdenk		Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
701c609719bSwdenk		write routine for first time initialisation.
702c609719bSwdenk
703c609719bSwdenk		CONFIG_TULIP
704c609719bSwdenk		Support for Digital 2114x chips.
705c609719bSwdenk		Optional CONFIG_TULIP_SELECT_MEDIA for board specific
706c609719bSwdenk		modem chip initialisation (KS8761/QS6611).
707c609719bSwdenk
708c609719bSwdenk		CONFIG_NATSEMI
709c609719bSwdenk		Support for National dp83815 chips.
710c609719bSwdenk
711c609719bSwdenk		CONFIG_NS8382X
712c609719bSwdenk		Support for National dp8382[01] gigabit chips.
713c609719bSwdenk
71445219c46Swdenk- NETWORK Support (other):
71545219c46Swdenk
71645219c46Swdenk		CONFIG_DRIVER_LAN91C96
71745219c46Swdenk		Support for SMSC's LAN91C96 chips.
71845219c46Swdenk
71945219c46Swdenk			CONFIG_LAN91C96_BASE
72045219c46Swdenk			Define this to hold the physical address
72145219c46Swdenk			of the LAN91C96's I/O space
72245219c46Swdenk
72345219c46Swdenk			CONFIG_LAN91C96_USE_32_BIT
72445219c46Swdenk			Define this to enable 32 bit addressing
72545219c46Swdenk
726c609719bSwdenk- USB Support:
727c609719bSwdenk		At the moment only the UHCI host controller is
728c609719bSwdenk		supported (PIP405, MIP405); define
729c609719bSwdenk		CONFIG_USB_UHCI to enable it.
730c609719bSwdenk		define CONFIG_USB_KEYBOARD to enable the USB Keyboard
731c609719bSwdenk		end define CONFIG_USB_STORAGE to enable the USB
732c609719bSwdenk		storage devices.
733c609719bSwdenk		Note:
734c609719bSwdenk		Supported are USB Keyboards and USB Floppy drives
735c609719bSwdenk		(TEAC FD-05PUB).
736c609719bSwdenk
73771f95118Swdenk- MMC Support:
73871f95118Swdenk  		The MMC controller on the Intel PXA is supported. To
73971f95118Swdenk		enable this define CONFIG_MMC. The MMC can be
74071f95118Swdenk		accessed from the boot prompt by mapping the device
74171f95118Swdenk		to physical memory similar to flash. Command line is
74271f95118Swdenk		enabled with CFG_CMD_MMC. The MMC driver also works with
74371f95118Swdenk		the FAT fs. This is enabled with CFG_CMD_FAT.
74471f95118Swdenk
745c609719bSwdenk- Keyboard Support:
746c609719bSwdenk		CONFIG_ISA_KEYBOARD
747c609719bSwdenk
748c609719bSwdenk		Define this to enable standard (PC-Style) keyboard
749c609719bSwdenk		support
750c609719bSwdenk
751c609719bSwdenk		CONFIG_I8042_KBD
752c609719bSwdenk		Standard PC keyboard driver with US (is default) and
753c609719bSwdenk		GERMAN key layout (switch via environment 'keymap=de') support.
754c609719bSwdenk		Export function i8042_kbd_init, i8042_tstc and i8042_getc
755c609719bSwdenk		for cfb_console. Supports cursor blinking.
756c609719bSwdenk
757c609719bSwdenk- Video support:
758c609719bSwdenk		CONFIG_VIDEO
759c609719bSwdenk
760c609719bSwdenk		Define this to enable video support (for output to
761c609719bSwdenk		video).
762c609719bSwdenk
763c609719bSwdenk		CONFIG_VIDEO_CT69000
764c609719bSwdenk
765c609719bSwdenk		Enable Chips & Technologies 69000 Video chip
766c609719bSwdenk
767c609719bSwdenk		CONFIG_VIDEO_SMI_LYNXEM
768c609719bSwdenk		Enable Silicon Motion SMI 712/710/810 Video chip
769c609719bSwdenk		Videomode are selected via environment 'videomode' with
770c609719bSwdenk		standard LiLo mode numbers.
771c609719bSwdenk		Following modes are supported  (* is default):
772c609719bSwdenk
773c609719bSwdenk			    800x600  1024x768  1280x1024
774c609719bSwdenk	      256  (8bit)     303*      305       307
775c609719bSwdenk	    65536 (16bit)     314       317       31a
776c609719bSwdenk	16,7 Mill (24bit)     315       318       31b
777c609719bSwdenk		(i.e. setenv videomode 317; saveenv; reset;)
778c609719bSwdenk
779a6c7ad2fSwdenk		CONFIG_VIDEO_SED13806
780a6c7ad2fSwdenk		Enable Epson SED13806 driver. This driver supports 8bpp
781a6c7ad2fSwdenk		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
782a6c7ad2fSwdenk		or CONFIG_VIDEO_SED13806_16BPP
783a6c7ad2fSwdenk
784682011ffSwdenk- Keyboard Support:
785682011ffSwdenk                CONFIG_KEYBOARD
786682011ffSwdenk
787682011ffSwdenk                Define this to enable a custom keyboard support.
788682011ffSwdenk                This simply calls drv_keyboard_init() which must be
789682011ffSwdenk                defined in your board-specific files.
790682011ffSwdenk                The only board using this so far is RBC823.
791a6c7ad2fSwdenk
792c609719bSwdenk- LCD Support:	CONFIG_LCD
793c609719bSwdenk
794c609719bSwdenk		Define this to enable LCD support (for output to LCD
795c609719bSwdenk		display); also select one of the supported displays
796c609719bSwdenk		by defining one of these:
797c609719bSwdenk
798c609719bSwdenk		CONFIG_NEC_NL6648AC33:
799c609719bSwdenk
800c609719bSwdenk			NEC NL6648AC33-18. Active, color, single scan.
801c609719bSwdenk
802c609719bSwdenk		CONFIG_NEC_NL6648BC20
803c609719bSwdenk
804c609719bSwdenk			NEC NL6648BC20-08. 6.5", 640x480.
805c609719bSwdenk			Active, color, single scan.
806c609719bSwdenk
807c609719bSwdenk		CONFIG_SHARP_16x9
808c609719bSwdenk
809c609719bSwdenk			Sharp 320x240. Active, color, single scan.
810c609719bSwdenk			It isn't 16x9, and I am not sure what it is.
811c609719bSwdenk
812c609719bSwdenk		CONFIG_SHARP_LQ64D341
813c609719bSwdenk
814c609719bSwdenk			Sharp LQ64D341 display, 640x480.
815c609719bSwdenk			Active, color, single scan.
816c609719bSwdenk
817c609719bSwdenk		CONFIG_HLD1045
818c609719bSwdenk
819c609719bSwdenk			HLD1045 display, 640x480.
820c609719bSwdenk			Active, color, single scan.
821c609719bSwdenk
822c609719bSwdenk		CONFIG_OPTREX_BW
823c609719bSwdenk
824c609719bSwdenk			Optrex	 CBL50840-2 NF-FW 99 22 M5
825c609719bSwdenk			or
826c609719bSwdenk			Hitachi	 LMG6912RPFC-00T
827c609719bSwdenk			or
828c609719bSwdenk			Hitachi	 SP14Q002
829c609719bSwdenk
830c609719bSwdenk			320x240. Black & white.
831c609719bSwdenk
832c609719bSwdenk		Normally display is black on white background; define
833c609719bSwdenk		CFG_WHITE_ON_BLACK to get it inverted.
834c609719bSwdenk
835d791b1dcSwdenk- Spash Screen Support: CONFIG_SPLASH_SCREEN
836d791b1dcSwdenk
837d791b1dcSwdenk                If this option is set, the environment is checked for
838d791b1dcSwdenk                a variable "splashimage". If found, the usual display
839d791b1dcSwdenk                of logo, copyright and system information on the LCD
840d791b1dcSwdenk                is supressed and the BMP image at the address
841d791b1dcSwdenk                specified in "splashimage" is loaded instead. The
842d791b1dcSwdenk                console is redirected to the "nulldev", too. This
843d791b1dcSwdenk                allows for a "silent" boot where a splash screen is
844d791b1dcSwdenk                loaded very quickly after power-on.
845d791b1dcSwdenk
846d791b1dcSwdenk
847c609719bSwdenk- Ethernet address:
848c609719bSwdenk		CONFIG_ETHADDR
849c609719bSwdenk		CONFIG_ETH2ADDR
850c609719bSwdenk		CONFIG_ETH3ADDR
851c609719bSwdenk
852c609719bSwdenk		Define a default value for ethernet address to use
853c609719bSwdenk		for the respective ethernet interface, in case this
854c609719bSwdenk		is not determined automatically.
855c609719bSwdenk
856c609719bSwdenk- IP address:
857c609719bSwdenk		CONFIG_IPADDR
858c609719bSwdenk
859c609719bSwdenk		Define a default value for the IP address to use for
860c609719bSwdenk		the default ethernet interface, in case this is not
861c609719bSwdenk		determined through e.g. bootp.
862c609719bSwdenk
863c609719bSwdenk- Server IP address:
864c609719bSwdenk		CONFIG_SERVERIP
865c609719bSwdenk
866c609719bSwdenk		Defines a default value for theIP address of a TFTP
867c609719bSwdenk		server to contact when using the "tftboot" command.
868c609719bSwdenk
869c609719bSwdenk- BOOTP Recovery Mode:
870c609719bSwdenk		CONFIG_BOOTP_RANDOM_DELAY
871c609719bSwdenk
872c609719bSwdenk		If you have many targets in a network that try to
873c609719bSwdenk		boot using BOOTP, you may want to avoid that all
874c609719bSwdenk		systems send out BOOTP requests at precisely the same
875c609719bSwdenk		moment (which would happen for instance at recovery
876c609719bSwdenk		from a power failure, when all systems will try to
877c609719bSwdenk		boot, thus flooding the BOOTP server. Defining
878c609719bSwdenk		CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
879c609719bSwdenk		inserted before sending out BOOTP requests. The
880c609719bSwdenk		following delays are insterted then:
881c609719bSwdenk
882c609719bSwdenk		1st BOOTP request:	delay 0 ... 1 sec
883c609719bSwdenk		2nd BOOTP request:	delay 0 ... 2 sec
884c609719bSwdenk		3rd BOOTP request:	delay 0 ... 4 sec
885c609719bSwdenk		4th and following
886c609719bSwdenk		BOOTP requests:		delay 0 ... 8 sec
887c609719bSwdenk
888c609719bSwdenk- Status LED:	CONFIG_STATUS_LED
889c609719bSwdenk
890c609719bSwdenk		Several configurations allow to display the current
891c609719bSwdenk		status using a LED. For instance, the LED will blink
892c609719bSwdenk		fast while running U-Boot code, stop blinking as
893c609719bSwdenk		soon as a reply to a BOOTP request was received, and
894c609719bSwdenk		start blinking slow once the Linux kernel is running
895c609719bSwdenk		(supported by a status LED driver in the Linux
896c609719bSwdenk		kernel). Defining CONFIG_STATUS_LED enables this
897c609719bSwdenk		feature in U-Boot.
898c609719bSwdenk
899c609719bSwdenk- CAN Support:	CONFIG_CAN_DRIVER
900c609719bSwdenk
901c609719bSwdenk		Defining CONFIG_CAN_DRIVER enables CAN driver support
902c609719bSwdenk		on those systems that support this (optional)
903c609719bSwdenk		feature, like the TQM8xxL modules.
904c609719bSwdenk
905c609719bSwdenk- I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C
906c609719bSwdenk
907c609719bSwdenk		Enables I2C serial bus commands.  If this is selected,
908c609719bSwdenk		either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
909c609719bSwdenk		to include the appropriate I2C driver.
910c609719bSwdenk
911c609719bSwdenk		See also: common/cmd_i2c.c for a description of the
912c609719bSwdenk		command line interface.
913c609719bSwdenk
914c609719bSwdenk
915c609719bSwdenk		CONFIG_HARD_I2C
916c609719bSwdenk
917c609719bSwdenk		Selects the CPM hardware driver for I2C.
918c609719bSwdenk
919c609719bSwdenk		CONFIG_SOFT_I2C
920c609719bSwdenk
921c609719bSwdenk		Use software (aka bit-banging) driver instead of CPM
922c609719bSwdenk		or similar hardware support for I2C.  This is configured
923c609719bSwdenk		via the following defines.
924c609719bSwdenk
925c609719bSwdenk		I2C_INIT
926c609719bSwdenk
927c609719bSwdenk		(Optional). Any commands necessary to enable I2C
928c609719bSwdenk		controller or configure ports.
929c609719bSwdenk
930c609719bSwdenk		I2C_PORT
931c609719bSwdenk
932c609719bSwdenk		(Only for MPC8260 CPU). The I/O port to use (the code
933c609719bSwdenk		assumes both bits are on the same port). Valid values
934c609719bSwdenk		are 0..3 for ports A..D.
935c609719bSwdenk
936c609719bSwdenk		I2C_ACTIVE
937c609719bSwdenk
938c609719bSwdenk		The code necessary to make the I2C data line active
939c609719bSwdenk		(driven).  If the data line is open collector, this
940c609719bSwdenk		define can be null.
941c609719bSwdenk
942c609719bSwdenk		I2C_TRISTATE
943c609719bSwdenk
944c609719bSwdenk		The code necessary to make the I2C data line tri-stated
945c609719bSwdenk		(inactive).  If the data line is open collector, this
946c609719bSwdenk		define can be null.
947c609719bSwdenk
948c609719bSwdenk		I2C_READ
949c609719bSwdenk
950c609719bSwdenk		Code that returns TRUE if the I2C data line is high,
951c609719bSwdenk		FALSE if it is low.
952c609719bSwdenk
953c609719bSwdenk		I2C_SDA(bit)
954c609719bSwdenk
955c609719bSwdenk		If <bit> is TRUE, sets the I2C data line high. If it
956c609719bSwdenk		is FALSE, it clears it (low).
957c609719bSwdenk
958c609719bSwdenk		I2C_SCL(bit)
959c609719bSwdenk
960c609719bSwdenk		If <bit> is TRUE, sets the I2C clock line high. If it
961c609719bSwdenk		is FALSE, it clears it (low).
962c609719bSwdenk
963c609719bSwdenk		I2C_DELAY
964c609719bSwdenk
965c609719bSwdenk		This delay is invoked four times per clock cycle so this
966c609719bSwdenk		controls the rate of data transfer.  The data rate thus
967c609719bSwdenk		is 1 / (I2C_DELAY * 4).
968c609719bSwdenk
96947cd00faSwdenk		CFG_I2C_INIT_BOARD
97047cd00faSwdenk
97147cd00faSwdenk                When a board is reset during an i2c bus transfer
97247cd00faSwdenk                chips might think that the current transfer is still
97347cd00faSwdenk                in progress. On some boards it is possible to access
97447cd00faSwdenk                the i2c SCLK line directly, either by using the
97547cd00faSwdenk                processor pin as a GPIO or by having a second pin
97647cd00faSwdenk                connected to the bus. If this option is defined a
97747cd00faSwdenk                custom i2c_init_board() routine in boards/xxx/board.c
97847cd00faSwdenk                is run early in the boot sequence.
97947cd00faSwdenk
980c609719bSwdenk- SPI Support:	CONFIG_SPI
981c609719bSwdenk
982c609719bSwdenk		Enables SPI driver (so far only tested with
983c609719bSwdenk		SPI EEPROM, also an instance works with Crystal A/D and
984c609719bSwdenk		D/As on the SACSng board)
985c609719bSwdenk
986c609719bSwdenk		CONFIG_SPI_X
987c609719bSwdenk
988c609719bSwdenk		Enables extended (16-bit) SPI EEPROM addressing.
989c609719bSwdenk		(symmetrical to CONFIG_I2C_X)
990c609719bSwdenk
991c609719bSwdenk		CONFIG_SOFT_SPI
992c609719bSwdenk
993c609719bSwdenk		Enables a software (bit-bang) SPI driver rather than
994c609719bSwdenk		using hardware support. This is a general purpose
995c609719bSwdenk		driver that only requires three general I/O port pins
996c609719bSwdenk		(two outputs, one input) to function. If this is
997c609719bSwdenk		defined, the board configuration must define several
998c609719bSwdenk		SPI configuration items (port pins to use, etc). For
999c609719bSwdenk		an example, see include/configs/sacsng.h.
1000c609719bSwdenk
1001c609719bSwdenk- FPGA Support: CONFIG_FPGA_COUNT
1002c609719bSwdenk
1003c609719bSwdenk		Specify the number of FPGA devices to support.
1004c609719bSwdenk
1005c609719bSwdenk		CONFIG_FPGA
1006c609719bSwdenk
1007c609719bSwdenk		Used to specify the types of FPGA devices. For
1008c609719bSwdenk		example,
1009c609719bSwdenk 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
1010c609719bSwdenk
1011c609719bSwdenk 		CFG_FPGA_PROG_FEEDBACK
1012c609719bSwdenk
1013c609719bSwdenk		Enable printing of hash marks during FPGA
1014c609719bSwdenk		configuration.
1015c609719bSwdenk
1016c609719bSwdenk		CFG_FPGA_CHECK_BUSY
1017c609719bSwdenk
1018c609719bSwdenk		Enable checks on FPGA configuration interface busy
1019c609719bSwdenk		status by the configuration function. This option
1020c609719bSwdenk		will require a board or device specific function to
1021c609719bSwdenk		be written.
1022c609719bSwdenk
1023c609719bSwdenk		CONFIG_FPGA_DELAY
1024c609719bSwdenk
1025c609719bSwdenk		If defined, a function that provides delays in the
1026c609719bSwdenk		FPGA configuration driver.
1027c609719bSwdenk
1028c609719bSwdenk		CFG_FPGA_CHECK_CTRLC
1029c609719bSwdenk
1030c609719bSwdenk		Allow Control-C to interrupt FPGA configuration
1031c609719bSwdenk
1032c609719bSwdenk		CFG_FPGA_CHECK_ERROR
1033c609719bSwdenk
1034c609719bSwdenk		Check for configuration errors during FPGA bitfile
1035c609719bSwdenk		loading. For example, abort during Virtex II
1036c609719bSwdenk		configuration if the INIT_B line goes low (which
1037c609719bSwdenk		indicated a CRC error).
1038c609719bSwdenk
1039c609719bSwdenk		CFG_FPGA_WAIT_INIT
1040c609719bSwdenk
1041c609719bSwdenk		Maximum time to wait for the INIT_B line to deassert
1042c609719bSwdenk		after PROB_B has been deasserted during a Virtex II
1043c609719bSwdenk		FPGA configuration sequence. The default time is 500 mS.
1044c609719bSwdenk
1045c609719bSwdenk		CFG_FPGA_WAIT_BUSY
1046c609719bSwdenk
1047c609719bSwdenk		Maximum time to wait for BUSY to deassert during
1048c609719bSwdenk		Virtex II FPGA configuration. The default is 5 mS.
1049c609719bSwdenk
1050c609719bSwdenk		CFG_FPGA_WAIT_CONFIG
1051c609719bSwdenk
1052c609719bSwdenk		Time to wait after FPGA configuration. The default is
1053c609719bSwdenk		200 mS.
1054c609719bSwdenk
1055c609719bSwdenk- FPGA Support:	CONFIG_FPGA_COUNT
1056c609719bSwdenk
1057c609719bSwdenk 		Specify the number of FPGA devices to support.
1058c609719bSwdenk
1059c609719bSwdenk 		CONFIG_FPGA
1060c609719bSwdenk
1061c609719bSwdenk 		Used to specify the types of FPGA devices.  For example,
1062c609719bSwdenk 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
1063c609719bSwdenk
1064c609719bSwdenk 		CFG_FPGA_PROG_FEEDBACK
1065c609719bSwdenk
1066c609719bSwdenk 		Enable printing of hash marks during FPGA configuration.
1067c609719bSwdenk
1068c609719bSwdenk		CFG_FPGA_CHECK_BUSY
1069c609719bSwdenk
1070c609719bSwdenk		Enable checks on FPGA configuration interface busy
1071c609719bSwdenk		status by the configuration function. This option
1072c609719bSwdenk		will require a board or device specific function to
1073c609719bSwdenk		be written.
1074c609719bSwdenk
1075c609719bSwdenk		CONFIG_FPGA_DELAY
1076c609719bSwdenk
1077c609719bSwdenk		If defined, a function that provides delays in the FPGA
1078c609719bSwdenk		configuration driver.
1079c609719bSwdenk
1080c609719bSwdenk		CFG_FPGA_CHECK_CTRLC
1081c609719bSwdenk		Allow Control-C to interrupt FPGA configuration
1082c609719bSwdenk
1083c609719bSwdenk		CFG_FPGA_CHECK_ERROR
1084c609719bSwdenk
1085c609719bSwdenk		Check for configuration errors during FPGA bitfile
1086c609719bSwdenk		loading. For example, abort during Virtex II
1087c609719bSwdenk		configuration if the INIT_B line goes low (which
1088c609719bSwdenk		indicated a CRC error).
1089c609719bSwdenk
1090c609719bSwdenk		CFG_FPGA_WAIT_INIT
1091c609719bSwdenk
1092c609719bSwdenk		Maximum time to wait for the INIT_B line to deassert
1093c609719bSwdenk		after PROB_B has been deasserted during a Virtex II
1094c609719bSwdenk		FPGA configuration sequence. The default time is 500
1095c609719bSwdenk		mS.
1096c609719bSwdenk
1097c609719bSwdenk		CFG_FPGA_WAIT_BUSY
1098c609719bSwdenk
1099c609719bSwdenk		Maximum time to wait for BUSY to deassert during
1100c609719bSwdenk		Virtex II FPGA configuration. The default is 5 mS.
1101c609719bSwdenk
1102c609719bSwdenk		CFG_FPGA_WAIT_CONFIG
1103c609719bSwdenk
1104c609719bSwdenk		Time to wait after FPGA configuration. The default is
1105c609719bSwdenk		200 mS.
1106c609719bSwdenk
1107c609719bSwdenk- Configuration Management:
1108c609719bSwdenk		CONFIG_IDENT_STRING
1109c609719bSwdenk
1110c609719bSwdenk		If defined, this string will be added to the U-Boot
1111c609719bSwdenk		version information (U_BOOT_VERSION)
1112c609719bSwdenk
1113c609719bSwdenk- Vendor Parameter Protection:
1114c609719bSwdenk
1115c609719bSwdenk		U-Boot considers the values of the environment
1116c609719bSwdenk		variables "serial#" (Board Serial Number) and
1117c609719bSwdenk		"ethaddr" (Ethernet Address) to bb parameters that
1118c609719bSwdenk		are set once by the board vendor / manufacturer, and
1119c609719bSwdenk		protects these variables from casual modification by
1120c609719bSwdenk		the user. Once set, these variables are read-only,
1121c609719bSwdenk		and write or delete attempts are rejected. You can
1122c609719bSwdenk		change this behviour:
1123c609719bSwdenk
1124c609719bSwdenk		If CONFIG_ENV_OVERWRITE is #defined in your config
1125c609719bSwdenk		file, the write protection for vendor parameters is
112647cd00faSwdenk		completely disabled. Anybody can change or delete
1127c609719bSwdenk		these parameters.
1128c609719bSwdenk
1129c609719bSwdenk		Alternatively, if you #define _both_ CONFIG_ETHADDR
1130c609719bSwdenk		_and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1131c609719bSwdenk		ethernet address is installed in the environment,
1132c609719bSwdenk		which can be changed exactly ONCE by the user. [The
1133c609719bSwdenk		serial# is unaffected by this, i. e. it remains
1134c609719bSwdenk		read-only.]
1135c609719bSwdenk
1136c609719bSwdenk- Protected RAM:
1137c609719bSwdenk		CONFIG_PRAM
1138c609719bSwdenk
1139c609719bSwdenk		Define this variable to enable the reservation of
1140c609719bSwdenk		"protected RAM", i. e. RAM which is not overwritten
1141c609719bSwdenk		by U-Boot. Define CONFIG_PRAM to hold the number of
1142c609719bSwdenk		kB you want to reserve for pRAM. You can overwrite
1143c609719bSwdenk		this default value by defining an environment
1144c609719bSwdenk		variable "pram" to the number of kB you want to
1145c609719bSwdenk		reserve. Note that the board info structure will
1146c609719bSwdenk		still show the full amount of RAM. If pRAM is
1147c609719bSwdenk		reserved, a new environment variable "mem" will
1148c609719bSwdenk		automatically be defined to hold the amount of
1149c609719bSwdenk		remaining RAM in a form that can be passed as boot
1150c609719bSwdenk		argument to Linux, for instance like that:
1151c609719bSwdenk
1152c609719bSwdenk			setenv bootargs ... mem=\$(mem)
1153c609719bSwdenk			saveenv
1154c609719bSwdenk
1155c609719bSwdenk		This way you can tell Linux not to use this memory,
1156c609719bSwdenk		either, which results in a memory region that will
1157c609719bSwdenk		not be affected by reboots.
1158c609719bSwdenk
1159c609719bSwdenk		*WARNING* If your board configuration uses automatic
1160c609719bSwdenk		detection of the RAM size, you must make sure that
1161c609719bSwdenk		this memory test is non-destructive. So far, the
1162c609719bSwdenk		following board configurations are known to be
1163c609719bSwdenk		"pRAM-clean":
1164c609719bSwdenk
1165c609719bSwdenk			ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1166c609719bSwdenk			HERMES, IP860, RPXlite, LWMON, LANTEC,
1167c609719bSwdenk			PCU_E, FLAGADM, TQM8260
1168c609719bSwdenk
1169c609719bSwdenk- Error Recovery:
1170c609719bSwdenk		CONFIG_PANIC_HANG
1171c609719bSwdenk
1172c609719bSwdenk		Define this variable to stop the system in case of a
1173c609719bSwdenk		fatal error, so that you have to reset it manually.
1174c609719bSwdenk		This is probably NOT a good idea for an embedded
1175c609719bSwdenk		system where you want to system to reboot
1176c609719bSwdenk		automatically as fast as possible, but it may be
1177c609719bSwdenk		useful during development since you can try to debug
1178c609719bSwdenk		the conditions that lead to the situation.
1179c609719bSwdenk
1180c609719bSwdenk		CONFIG_NET_RETRY_COUNT
1181c609719bSwdenk
1182c609719bSwdenk		This variable defines the number of retries for
1183c609719bSwdenk		network operations like ARP, RARP, TFTP, or BOOTP
1184c609719bSwdenk		before giving up the operation. If not defined, a
1185c609719bSwdenk		default value of 5 is used.
1186c609719bSwdenk
1187c609719bSwdenk- Command Interpreter:
1188c609719bSwdenk		CFG_HUSH_PARSER
1189c609719bSwdenk
1190c609719bSwdenk		Define this variable to enable the "hush" shell (from
1191c609719bSwdenk		Busybox) as command line interpreter, thus enabling
1192c609719bSwdenk		powerful command line syntax like
1193c609719bSwdenk		if...then...else...fi conditionals or `&&' and '||'
1194c609719bSwdenk		constructs ("shell scripts").
1195c609719bSwdenk
1196c609719bSwdenk		If undefined, you get the old, much simpler behaviour
1197c609719bSwdenk		with a somewhat smaller memory footprint.
1198c609719bSwdenk
1199c609719bSwdenk
1200c609719bSwdenk		CFG_PROMPT_HUSH_PS2
1201c609719bSwdenk
1202c609719bSwdenk		This defines the secondary prompt string, which is
1203c609719bSwdenk		printed when the command interpreter needs more input
1204c609719bSwdenk		to complete a command. Usually "> ".
1205c609719bSwdenk
1206c609719bSwdenk	Note:
1207c609719bSwdenk
1208c609719bSwdenk                In the current implementation, the local variables
1209c609719bSwdenk                space and global environment variables space are
1210c609719bSwdenk                separated. Local variables are those you define by
12113b57fe0aSwdenk                simply typing `name=value'. To access a local
1212c609719bSwdenk                variable later on, you have write `$name' or
12133b57fe0aSwdenk                `${name}'; to execute the contents of a variable
12143b57fe0aSwdenk                directly type `$name' at the command prompt.
1215c609719bSwdenk
1216c609719bSwdenk		Global environment variables are those you use
1217c609719bSwdenk		setenv/printenv to work with. To run a command stored
1218c609719bSwdenk		in such a variable, you need to use the run command,
1219c609719bSwdenk		and you must not use the '$' sign to access them.
1220c609719bSwdenk
1221c609719bSwdenk		To store commands and special characters in a
1222c609719bSwdenk		variable, please use double quotation marks
1223c609719bSwdenk		surrounding the whole text of the variable, instead
1224c609719bSwdenk		of the backslashes before semicolons and special
1225c609719bSwdenk		symbols.
1226c609719bSwdenk
1227c609719bSwdenk- Default Environment
1228c609719bSwdenk		CONFIG_EXTRA_ENV_SETTINGS
1229c609719bSwdenk
1230c609719bSwdenk		Define this to contain any number of null terminated
1231c609719bSwdenk		strings (variable = value pairs) that will be part of
1232c609719bSwdenk		the default enviroment compiled into the boot image.
12332262cfeeSwdenk
1234c609719bSwdenk		For example, place something like this in your
1235c609719bSwdenk		board's config file:
1236c609719bSwdenk
1237c609719bSwdenk		#define CONFIG_EXTRA_ENV_SETTINGS \
1238c609719bSwdenk			"myvar1=value1\0" \
1239c609719bSwdenk			"myvar2=value2\0"
1240c609719bSwdenk
1241c609719bSwdenk		Warning: This method is based on knowledge about the
1242c609719bSwdenk		internal format how the environment is stored by the
12432262cfeeSwdenk		U-Boot code. This is NOT an official, exported
1244c609719bSwdenk		interface! Although it is unlikely that this format
12452262cfeeSwdenk		will change soon, but there is no guarantee either.
1246c609719bSwdenk		You better know what you are doing here.
1247c609719bSwdenk
1248c609719bSwdenk		Note: overly (ab)use of the default environment is
1249c609719bSwdenk		discouraged. Make sure to check other ways to preset
1250c609719bSwdenk		the environment like the autoscript function or the
1251c609719bSwdenk		boot command first.
1252c609719bSwdenk
12532abbe075Swdenk- DataFlash Support
12542abbe075Swdenk		CONFIG_HAS_DATAFLASH
12552abbe075Swdenk
12562abbe075Swdenk                Defining this option enables DataFlash features and
12572abbe075Swdenk                allows to read/write in Dataflash via the standard
12582abbe075Swdenk                commands cp, md...
12592abbe075Swdenk
1260c609719bSwdenk- Show boot progress
1261c609719bSwdenk		CONFIG_SHOW_BOOT_PROGRESS
1262c609719bSwdenk
1263c609719bSwdenk		Defining this option allows to add some board-
1264c609719bSwdenk		specific code (calling a user-provided function
1265c609719bSwdenk		"show_boot_progress(int)") that enables you to show
1266c609719bSwdenk		the system's boot progress on some display (for
1267c609719bSwdenk		example, some LED's) on your board. At the moment,
1268c609719bSwdenk		the following checkpoints are implemented:
1269c609719bSwdenk
1270c609719bSwdenk  Arg	Where			When
1271c609719bSwdenk    1	common/cmd_bootm.c	before attempting to boot an image
1272c609719bSwdenk   -1	common/cmd_bootm.c	Image header has bad     magic number
1273c609719bSwdenk    2	common/cmd_bootm.c	Image header has correct magic number
1274c609719bSwdenk   -2	common/cmd_bootm.c	Image header has bad     checksum
1275c609719bSwdenk    3	common/cmd_bootm.c	Image header has correct checksum
1276c609719bSwdenk   -3	common/cmd_bootm.c	Image data   has bad     checksum
1277c609719bSwdenk    4	common/cmd_bootm.c	Image data   has correct checksum
1278c609719bSwdenk   -4	common/cmd_bootm.c	Image is for unsupported architecture
1279c609719bSwdenk    5	common/cmd_bootm.c	Architecture check OK
1280c609719bSwdenk   -5	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1281c609719bSwdenk    6	common/cmd_bootm.c	Image Type check OK
1282c609719bSwdenk   -6	common/cmd_bootm.c	gunzip uncompression error
1283c609719bSwdenk   -7	common/cmd_bootm.c	Unimplemented compression type
1284c609719bSwdenk    7	common/cmd_bootm.c	Uncompression OK
1285c609719bSwdenk   -8	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1286c609719bSwdenk    8	common/cmd_bootm.c	Image Type check OK
1287c609719bSwdenk   -9	common/cmd_bootm.c	Unsupported OS (not Linux, BSD, VxWorks, QNX)
1288c609719bSwdenk    9	common/cmd_bootm.c	Start initial ramdisk verification
1289c609719bSwdenk  -10	common/cmd_bootm.c	Ramdisk header has bad     magic number
1290c609719bSwdenk  -11	common/cmd_bootm.c	Ramdisk header has bad     checksum
1291c609719bSwdenk   10	common/cmd_bootm.c	Ramdisk header is OK
1292c609719bSwdenk  -12	common/cmd_bootm.c	Ramdisk data   has bad     checksum
1293c609719bSwdenk   11	common/cmd_bootm.c	Ramdisk data   has correct checksum
1294c609719bSwdenk   12	common/cmd_bootm.c	Ramdisk verification complete, start loading
1295c609719bSwdenk  -13	common/cmd_bootm.c	Wrong Image Type (not PPC Linux Ramdisk)
1296c609719bSwdenk   13	common/cmd_bootm.c	Start multifile image verification
1297c609719bSwdenk   14	common/cmd_bootm.c	No initial ramdisk, no multifile, continue.
1298c609719bSwdenk   15	common/cmd_bootm.c	All preparation done, transferring control to OS
1299c609719bSwdenk
1300c609719bSwdenk   -1	common/cmd_doc.c	Bad usage of "doc" command
1301c609719bSwdenk   -1	common/cmd_doc.c	No boot device
1302c609719bSwdenk   -1	common/cmd_doc.c	Unknown Chip ID on boot device
1303c609719bSwdenk   -1	common/cmd_doc.c	Read Error on boot device
1304c609719bSwdenk   -1	common/cmd_doc.c	Image header has bad magic number
1305c609719bSwdenk
1306c609719bSwdenk   -1	common/cmd_ide.c	Bad usage of "ide" command
1307c609719bSwdenk   -1	common/cmd_ide.c	No boot device
1308c609719bSwdenk   -1	common/cmd_ide.c	Unknown boot device
1309c609719bSwdenk   -1	common/cmd_ide.c	Unknown partition table
1310c609719bSwdenk   -1	common/cmd_ide.c	Invalid partition type
1311c609719bSwdenk   -1	common/cmd_ide.c	Read Error on boot device
1312c609719bSwdenk   -1	common/cmd_ide.c	Image header has bad magic number
1313c609719bSwdenk
1314c609719bSwdenk   -1	common/cmd_nvedit.c	Environment not changable, but has bad CRC
1315c609719bSwdenk
1316c609719bSwdenk
1317c609719bSwdenkModem Support:
1318c609719bSwdenk--------------
1319c609719bSwdenk
132085ec0bccSwdenk[so far only for SMDK2400 and TRAB boards]
1321c609719bSwdenk
1322c609719bSwdenk- Modem support endable:
1323c609719bSwdenk		CONFIG_MODEM_SUPPORT
1324c609719bSwdenk
1325c609719bSwdenk- RTS/CTS Flow control enable:
1326c609719bSwdenk		CONFIG_HWFLOW
1327c609719bSwdenk
1328c609719bSwdenk- Modem debug support:
1329c609719bSwdenk		CONFIG_MODEM_SUPPORT_DEBUG
1330c609719bSwdenk
1331c609719bSwdenk		Enables debugging stuff (char screen[1024], dbg())
1332c609719bSwdenk		for modem support. Useful only with BDI2000.
1333c609719bSwdenk
1334c609719bSwdenk- General:
1335c609719bSwdenk
1336c609719bSwdenk		In the target system modem support is enabled when a
1337c609719bSwdenk		specific key (key combination) is pressed during
1338c609719bSwdenk		power-on. Otherwise U-Boot will boot normally
1339c609719bSwdenk		(autoboot). The key_pressed() fuction is called from
1340c609719bSwdenk		board_init(). Currently key_pressed() is a dummy
1341c609719bSwdenk		function, returning 1 and thus enabling modem
1342c609719bSwdenk		initialization.
1343c609719bSwdenk
1344c609719bSwdenk		If there are no modem init strings in the
1345c609719bSwdenk		environment, U-Boot proceed to autoboot; the
1346c609719bSwdenk		previous output (banner, info printfs) will be
1347c609719bSwdenk		supressed, though.
1348c609719bSwdenk
1349c609719bSwdenk		See also: doc/README.Modem
1350c609719bSwdenk
1351c609719bSwdenk
1352c609719bSwdenk
1353c609719bSwdenk
1354c609719bSwdenkConfiguration Settings:
1355c609719bSwdenk-----------------------
1356c609719bSwdenk
1357c609719bSwdenk- CFG_LONGHELP: Defined when you want long help messages included;
1358c609719bSwdenk		undefine this when you're short of memory.
1359c609719bSwdenk
1360c609719bSwdenk- CFG_PROMPT:	This is what U-Boot prints on the console to
1361c609719bSwdenk		prompt for user input.
1362c609719bSwdenk
1363c609719bSwdenk- CFG_CBSIZE:	Buffer size for input from the Console
1364c609719bSwdenk
1365c609719bSwdenk- CFG_PBSIZE:	Buffer size for Console output
1366c609719bSwdenk
1367c609719bSwdenk- CFG_MAXARGS:	max. Number of arguments accepted for monitor commands
1368c609719bSwdenk
1369c609719bSwdenk- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1370c609719bSwdenk		the application (usually a Linux kernel) when it is
1371c609719bSwdenk		booted
1372c609719bSwdenk
1373c609719bSwdenk- CFG_BAUDRATE_TABLE:
1374c609719bSwdenk		List of legal baudrate settings for this board.
1375c609719bSwdenk
1376c609719bSwdenk- CFG_CONSOLE_INFO_QUIET
1377c609719bSwdenk 		Suppress display of console information at boot.
1378c609719bSwdenk
1379c609719bSwdenk- CFG_CONSOLE_IS_IN_ENV
1380c609719bSwdenk 		If the board specific function
1381c609719bSwdenk 			extern int overwrite_console (void);
1382c609719bSwdenk 		returns 1, the stdin, stderr and stdout are switched to the
1383c609719bSwdenk		serial port, else the settings in the environment are used.
1384c609719bSwdenk
1385c609719bSwdenk- CFG_CONSOLE_OVERWRITE_ROUTINE
1386c609719bSwdenk 		Enable the call to overwrite_console().
1387c609719bSwdenk
1388c609719bSwdenk- CFG_CONSOLE_ENV_OVERWRITE
1389c609719bSwdenk		Enable overwrite of previous console environment settings.
1390c609719bSwdenk
1391c609719bSwdenk- CFG_MEMTEST_START, CFG_MEMTEST_END:
1392c609719bSwdenk		Begin and End addresses of the area used by the
1393c609719bSwdenk		simple memory test.
1394c609719bSwdenk
1395c609719bSwdenk- CFG_ALT_MEMTEST:
1396c609719bSwdenk 		Enable an alternate, more extensive memory test.
1397c609719bSwdenk
1398c609719bSwdenk- CFG_TFTP_LOADADDR:
1399c609719bSwdenk		Default load address for network file downloads
1400c609719bSwdenk
1401c609719bSwdenk- CFG_LOADS_BAUD_CHANGE:
1402c609719bSwdenk		Enable temporary baudrate change while serial download
1403c609719bSwdenk
1404c609719bSwdenk- CFG_SDRAM_BASE:
1405c609719bSwdenk		Physical start address of SDRAM. _Must_ be 0 here.
1406c609719bSwdenk
1407c609719bSwdenk- CFG_MBIO_BASE:
1408c609719bSwdenk		Physical start address of Motherboard I/O (if using a
1409c609719bSwdenk		Cogent motherboard)
1410c609719bSwdenk
1411c609719bSwdenk- CFG_FLASH_BASE:
1412c609719bSwdenk		Physical start address of Flash memory.
1413c609719bSwdenk
1414c609719bSwdenk- CFG_MONITOR_BASE:
1415c609719bSwdenk		Physical start address of boot monitor code (set by
1416c609719bSwdenk		make config files to be same as the text base address
1417c609719bSwdenk		(TEXT_BASE) used when linking) - same as
1418c609719bSwdenk		CFG_FLASH_BASE when booting from flash.
1419c609719bSwdenk
1420c609719bSwdenk- CFG_MONITOR_LEN:
14213b57fe0aSwdenk                Size of memory reserved for monitor code, used to
14223b57fe0aSwdenk                determine _at_compile_time_ (!) if the environment is
14233b57fe0aSwdenk                embedded within the U-Boot image, or in a separate
14243b57fe0aSwdenk                flash sector.
1425c609719bSwdenk
1426c609719bSwdenk- CFG_MALLOC_LEN:
1427c609719bSwdenk		Size of DRAM reserved for malloc() use.
1428c609719bSwdenk
1429c609719bSwdenk- CFG_BOOTMAPSZ:
1430c609719bSwdenk		Maximum size of memory mapped by the startup code of
1431c609719bSwdenk		the Linux kernel; all data that must be processed by
1432c609719bSwdenk		the Linux kernel (bd_info, boot arguments, eventually
1433c609719bSwdenk		initrd image) must be put below this limit.
1434c609719bSwdenk
1435c609719bSwdenk- CFG_MAX_FLASH_BANKS:
1436c609719bSwdenk		Max number of Flash memory banks
1437c609719bSwdenk
1438c609719bSwdenk- CFG_MAX_FLASH_SECT:
1439c609719bSwdenk		Max number of sectors on a Flash chip
1440c609719bSwdenk
1441c609719bSwdenk- CFG_FLASH_ERASE_TOUT:
1442c609719bSwdenk		Timeout for Flash erase operations (in ms)
1443c609719bSwdenk
1444c609719bSwdenk- CFG_FLASH_WRITE_TOUT:
1445c609719bSwdenk		Timeout for Flash write operations (in ms)
1446c609719bSwdenk
1447c609719bSwdenk- CFG_DIRECT_FLASH_TFTP:
1448c609719bSwdenk
1449c609719bSwdenk		Enable TFTP transfers directly to flash memory;
1450c609719bSwdenk		without this option such a download has to be
1451c609719bSwdenk		performed in two steps: (1) download to RAM, and (2)
1452c609719bSwdenk		copy from RAM to flash.
1453c609719bSwdenk
1454c609719bSwdenk		The two-step approach is usually more reliable, since
1455c609719bSwdenk		you can check if the download worked before you erase
1456c609719bSwdenk		the flash, but in some situations (when sytem RAM is
1457c609719bSwdenk		too limited to allow for a tempory copy of the
1458c609719bSwdenk		downloaded image) this option may be very useful.
1459c609719bSwdenk
1460c609719bSwdenk- CFG_FLASH_CFI:
1461c609719bSwdenk		Define if the flash driver uses extra elements in the
1462c609719bSwdenk		common flash structure for storing flash geometry
146353cf9435Sstroese
146453cf9435Sstroese- CFG_RX_ETH_BUFFER:
146553cf9435Sstroese		Defines the number of ethernet receive buffers. On some
146653cf9435Sstroese		ethernet controllers it is recommended to set this value
146753cf9435Sstroese		to 8 or even higher (EEPRO100 or 405 EMAC), since all
146853cf9435Sstroese		buffers can be full shortly after enabling the interface
146953cf9435Sstroese		on high ethernet traffic.
147053cf9435Sstroese		Defaults to 4 if not defined.
1471c609719bSwdenk
1472c609719bSwdenkThe following definitions that deal with the placement and management
1473c609719bSwdenkof environment data (variable area); in general, we support the
1474c609719bSwdenkfollowing configurations:
1475c609719bSwdenk
1476c609719bSwdenk- CFG_ENV_IS_IN_FLASH:
1477c609719bSwdenk
1478c609719bSwdenk	Define this if the environment is in flash memory.
1479c609719bSwdenk
1480c609719bSwdenk	a) The environment occupies one whole flash sector, which is
1481c609719bSwdenk	   "embedded" in the text segment with the U-Boot code. This
1482c609719bSwdenk	   happens usually with "bottom boot sector" or "top boot
1483c609719bSwdenk	   sector" type flash chips, which have several smaller
1484c609719bSwdenk	   sectors at the start or the end. For instance, such a
1485c609719bSwdenk	   layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1486c609719bSwdenk	   such a case you would place the environment in one of the
1487c609719bSwdenk	   4 kB sectors - with U-Boot code before and after it. With
1488c609719bSwdenk	   "top boot sector" type flash chips, you would put the
1489c609719bSwdenk	   environment in one of the last sectors, leaving a gap
1490c609719bSwdenk	   between U-Boot and the environment.
1491c609719bSwdenk
1492c609719bSwdenk	- CFG_ENV_OFFSET:
1493c609719bSwdenk
1494c609719bSwdenk	   Offset of environment data (variable area) to the
1495c609719bSwdenk	   beginning of flash memory; for instance, with bottom boot
1496c609719bSwdenk	   type flash chips the second sector can be used: the offset
1497c609719bSwdenk	   for this sector is given here.
1498c609719bSwdenk
1499c609719bSwdenk	   CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1500c609719bSwdenk
1501c609719bSwdenk	- CFG_ENV_ADDR:
1502c609719bSwdenk
1503c609719bSwdenk	   This is just another way to specify the start address of
1504c609719bSwdenk	   the flash sector containing the environment (instead of
1505c609719bSwdenk	   CFG_ENV_OFFSET).
1506c609719bSwdenk
1507c609719bSwdenk	- CFG_ENV_SECT_SIZE:
1508c609719bSwdenk
1509c609719bSwdenk	   Size of the sector containing the environment.
1510c609719bSwdenk
1511c609719bSwdenk
1512c609719bSwdenk	b) Sometimes flash chips have few, equal sized, BIG sectors.
1513c609719bSwdenk	   In such a case you don't want to spend a whole sector for
1514c609719bSwdenk	   the environment.
1515c609719bSwdenk
1516c609719bSwdenk	- CFG_ENV_SIZE:
1517c609719bSwdenk
1518c609719bSwdenk	   If you use this in combination with CFG_ENV_IS_IN_FLASH
1519c609719bSwdenk	   and CFG_ENV_SECT_SIZE, you can specify to use only a part
1520c609719bSwdenk	   of this flash sector for the environment. This saves
1521c609719bSwdenk	   memory for the RAM copy of the environment.
1522c609719bSwdenk
1523c609719bSwdenk	   It may also save flash memory if you decide to use this
1524c609719bSwdenk	   when your environment is "embedded" within U-Boot code,
1525c609719bSwdenk	   since then the remainder of the flash sector could be used
1526c609719bSwdenk	   for U-Boot code. It should be pointed out that this is
1527c609719bSwdenk	   STRONGLY DISCOURAGED from a robustness point of view:
1528c609719bSwdenk	   updating the environment in flash makes it always
1529c609719bSwdenk	   necessary to erase the WHOLE sector. If something goes
1530c609719bSwdenk	   wrong before the contents has been restored from a copy in
1531c609719bSwdenk	   RAM, your target system will be dead.
1532c609719bSwdenk
1533c609719bSwdenk	- CFG_ENV_ADDR_REDUND
1534c609719bSwdenk	  CFG_ENV_SIZE_REDUND
1535c609719bSwdenk
1536c609719bSwdenk	   These settings describe a second storage area used to hold
1537c609719bSwdenk	   a redundand copy of the environment data, so that there is
15383e38691eSwdenk	   a valid backup copy in case there is a power failure during
1539c609719bSwdenk	   a "saveenv" operation.
1540c609719bSwdenk
1541c609719bSwdenkBE CAREFUL! Any changes to the flash layout, and some changes to the
1542c609719bSwdenksource code will make it necessary to adapt <board>/u-boot.lds*
1543c609719bSwdenkaccordingly!
1544c609719bSwdenk
1545c609719bSwdenk
1546c609719bSwdenk- CFG_ENV_IS_IN_NVRAM:
1547c609719bSwdenk
1548c609719bSwdenk	Define this if you have some non-volatile memory device
1549c609719bSwdenk	(NVRAM, battery buffered SRAM) which you want to use for the
1550c609719bSwdenk	environment.
1551c609719bSwdenk
1552c609719bSwdenk	- CFG_ENV_ADDR:
1553c609719bSwdenk	- CFG_ENV_SIZE:
1554c609719bSwdenk
1555c609719bSwdenk	  These two #defines are used to determin the memory area you
1556c609719bSwdenk	  want to use for environment. It is assumed that this memory
1557c609719bSwdenk	  can just be read and written to, without any special
1558c609719bSwdenk	  provision.
1559c609719bSwdenk
1560c609719bSwdenkBE CAREFUL! The first access to the environment happens quite early
1561c609719bSwdenkin U-Boot initalization (when we try to get the setting of for the
1562c609719bSwdenkconsole baudrate). You *MUST* have mappend your NVRAM area then, or
1563c609719bSwdenkU-Boot will hang.
1564c609719bSwdenk
1565c609719bSwdenkPlease note that even with NVRAM we still use a copy of the
1566c609719bSwdenkenvironment in RAM: we could work on NVRAM directly, but we want to
1567c609719bSwdenkkeep settings there always unmodified except somebody uses "saveenv"
1568c609719bSwdenkto save the current settings.
1569c609719bSwdenk
1570c609719bSwdenk
1571c609719bSwdenk- CFG_ENV_IS_IN_EEPROM:
1572c609719bSwdenk
1573c609719bSwdenk	Use this if you have an EEPROM or similar serial access
1574c609719bSwdenk	device and a driver for it.
1575c609719bSwdenk
1576c609719bSwdenk	- CFG_ENV_OFFSET:
1577c609719bSwdenk	- CFG_ENV_SIZE:
1578c609719bSwdenk
1579c609719bSwdenk	  These two #defines specify the offset and size of the
1580c609719bSwdenk	  environment area within the total memory of your EEPROM.
1581c609719bSwdenk
1582c609719bSwdenk	- CFG_I2C_EEPROM_ADDR:
1583c609719bSwdenk	  If defined, specified the chip address of the EEPROM device.
1584c609719bSwdenk	  The default address is zero.
1585c609719bSwdenk
1586c609719bSwdenk	- CFG_EEPROM_PAGE_WRITE_BITS:
1587c609719bSwdenk	  If defined, the number of bits used to address bytes in a
1588c609719bSwdenk	  single page in the EEPROM device.  A 64 byte page, for example
1589c609719bSwdenk	  would require six bits.
1590c609719bSwdenk
1591c609719bSwdenk	- CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1592c609719bSwdenk	  If defined, the number of milliseconds to delay between
1593c609719bSwdenk	  page writes.  The default is zero milliseconds.
1594c609719bSwdenk
1595c609719bSwdenk	- CFG_I2C_EEPROM_ADDR_LEN:
1596c609719bSwdenk	  The length in bytes of the EEPROM memory array address.  Note
1597c609719bSwdenk	  that this is NOT the chip address length!
1598c609719bSwdenk
1599c609719bSwdenk	- CFG_EEPROM_SIZE:
1600c609719bSwdenk	  The size in bytes of the EEPROM device.
1601c609719bSwdenk
1602c609719bSwdenk
1603c609719bSwdenk- CFG_SPI_INIT_OFFSET
1604c609719bSwdenk
1605c609719bSwdenk	Defines offset to the initial SPI buffer area in DPRAM. The
1606c609719bSwdenk	area is used at an early stage (ROM part) if the environment
1607c609719bSwdenk	is configured to reside in the SPI EEPROM: We need a 520 byte
1608c609719bSwdenk	scratch DPRAM area. It is used between the two initialization
1609c609719bSwdenk	calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1610c609719bSwdenk	to be a good choice since it makes it far enough from the
1611c609719bSwdenk	start of the data area as well as from the stack pointer.
1612c609719bSwdenk
1613c609719bSwdenkPlease note that the environment is read-only as long as the monitor
1614c609719bSwdenkhas been relocated to RAM and a RAM copy of the environment has been
1615c609719bSwdenkcreated; also, when using EEPROM you will have to use getenv_r()
1616c609719bSwdenkuntil then to read environment variables.
1617c609719bSwdenk
161885ec0bccSwdenkThe environment is protected by a CRC32 checksum. Before the monitor
161985ec0bccSwdenkis relocated into RAM, as a result of a bad CRC you will be working
162085ec0bccSwdenkwith the compiled-in default environment - *silently*!!! [This is
162185ec0bccSwdenknecessary, because the first environment variable we need is the
162285ec0bccSwdenk"baudrate" setting for the console - if we have a bad CRC, we don't
162385ec0bccSwdenkhave any device yet where we could complain.]
1624c609719bSwdenk
1625c609719bSwdenkNote: once the monitor has been relocated, then it will complain if
1626c609719bSwdenkthe default environment is used; a new CRC is computed as soon as you
162785ec0bccSwdenkuse the "saveenv" command to store a valid environment.
1628c609719bSwdenk
1629c609719bSwdenk
1630c609719bSwdenkLow Level (hardware related) configuration options:
1631dc7c9a1aSwdenk---------------------------------------------------
1632c609719bSwdenk
1633c609719bSwdenk- CFG_CACHELINE_SIZE:
1634c609719bSwdenk		Cache Line Size of the CPU.
1635c609719bSwdenk
1636c609719bSwdenk- CFG_DEFAULT_IMMR:
1637c609719bSwdenk		Default address of the IMMR after system reset.
1638c609719bSwdenk		Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1639c609719bSwdenk		to be able to adjust the position of the IMMR
1640c609719bSwdenk		register after a reset.
1641c609719bSwdenk
16427f6c2cbcSwdenk- Floppy Disk Support:
16437f6c2cbcSwdenk		CFG_FDC_DRIVE_NUMBER
16447f6c2cbcSwdenk
16457f6c2cbcSwdenk		the default drive number (default value 0)
16467f6c2cbcSwdenk
16477f6c2cbcSwdenk		CFG_ISA_IO_STRIDE
16487f6c2cbcSwdenk
16497f6c2cbcSwdenk		defines the spacing between fdc chipset registers
16507f6c2cbcSwdenk		(default value 1)
16517f6c2cbcSwdenk
16527f6c2cbcSwdenk		CFG_ISA_IO_OFFSET
16537f6c2cbcSwdenk
16547f6c2cbcSwdenk		defines the offset of register from address. It
16557f6c2cbcSwdenk		depends on which part of the data bus is connected to
16567f6c2cbcSwdenk		the fdc chipset. (default value 0)
16577f6c2cbcSwdenk
16587f6c2cbcSwdenk		If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
16597f6c2cbcSwdenk		CFG_FDC_DRIVE_NUMBER are undefined, they take their
16607f6c2cbcSwdenk		default value.
16617f6c2cbcSwdenk
16627f6c2cbcSwdenk		if CFG_FDC_HW_INIT is defined, then the function
16637f6c2cbcSwdenk		fdc_hw_init() is called at the beginning of the FDC
16647f6c2cbcSwdenk		setup. fdc_hw_init() must be provided by the board
16657f6c2cbcSwdenk		source code. It is used to make hardware dependant
16667f6c2cbcSwdenk		initializations.
16677f6c2cbcSwdenk
1668c609719bSwdenk- CFG_IMMR:	Physical address of the Internal Memory Mapped
1669c609719bSwdenk		Register; DO NOT CHANGE! (11-4)
1670c609719bSwdenk		[MPC8xx systems only]
1671c609719bSwdenk
1672c609719bSwdenk- CFG_INIT_RAM_ADDR:
1673c609719bSwdenk
1674c609719bSwdenk		Start address of memory area tha can be used for
1675c609719bSwdenk		initial data and stack; please note that this must be
1676c609719bSwdenk		writable memory that is working WITHOUT special
1677c609719bSwdenk		initialization, i. e. you CANNOT use normal RAM which
1678c609719bSwdenk		will become available only after programming the
1679c609719bSwdenk		memory controller and running certain initialization
1680c609719bSwdenk		sequences.
1681c609719bSwdenk
1682c609719bSwdenk		U-Boot uses the following memory types:
1683c609719bSwdenk		- MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1684c609719bSwdenk		- MPC824X: data cache
1685c609719bSwdenk		- PPC4xx:  data cache
1686c609719bSwdenk
168785ec0bccSwdenk- CFG_GBL_DATA_OFFSET:
1688c609719bSwdenk
1689c609719bSwdenk		Offset of the initial data structure in the memory
1690c609719bSwdenk		area defined by CFG_INIT_RAM_ADDR. Usually
169185ec0bccSwdenk		CFG_GBL_DATA_OFFSET is chosen such that the initial
1692c609719bSwdenk		data is located at the end of the available space
1693c609719bSwdenk		(sometimes written as (CFG_INIT_RAM_END -
1694c609719bSwdenk		CFG_INIT_DATA_SIZE), and the initial stack is just
1695c609719bSwdenk		below that area (growing from (CFG_INIT_RAM_ADDR +
169685ec0bccSwdenk		CFG_GBL_DATA_OFFSET) downward.
1697c609719bSwdenk
1698c609719bSwdenk	Note:
1699c609719bSwdenk		On the MPC824X (or other systems that use the data
1700c609719bSwdenk		cache for initial memory) the address chosen for
1701c609719bSwdenk		CFG_INIT_RAM_ADDR is basically arbitrary - it must
1702c609719bSwdenk		point to an otherwise UNUSED address space between
1703c609719bSwdenk		the top of RAM and the start of the PCI space.
1704c609719bSwdenk
1705c609719bSwdenk- CFG_SIUMCR:	SIU Module Configuration (11-6)
1706c609719bSwdenk
1707c609719bSwdenk- CFG_SYPCR:	System Protection Control (11-9)
1708c609719bSwdenk
1709c609719bSwdenk- CFG_TBSCR:	Time Base Status and Control (11-26)
1710c609719bSwdenk
1711c609719bSwdenk- CFG_PISCR:	Periodic Interrupt Status and Control (11-31)
1712c609719bSwdenk
1713c609719bSwdenk- CFG_PLPRCR:	PLL, Low-Power, and Reset Control Register (15-30)
1714c609719bSwdenk
1715c609719bSwdenk- CFG_SCCR:	System Clock and reset Control Register (15-27)
1716c609719bSwdenk
1717c609719bSwdenk- CFG_OR_TIMING_SDRAM:
1718c609719bSwdenk		SDRAM timing
1719c609719bSwdenk
1720c609719bSwdenk- CFG_MAMR_PTA:
1721c609719bSwdenk		periodic timer for refresh
1722c609719bSwdenk
1723c609719bSwdenk- CFG_DER:	Debug Event Register (37-47)
1724c609719bSwdenk
1725c609719bSwdenk- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1726c609719bSwdenk  CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1727c609719bSwdenk  CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1728c609719bSwdenk  CFG_BR1_PRELIM:
1729c609719bSwdenk		Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1730c609719bSwdenk
1731c609719bSwdenk- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1732c609719bSwdenk  CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1733c609719bSwdenk  CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1734c609719bSwdenk		Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1735c609719bSwdenk
1736c609719bSwdenk- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1737c609719bSwdenk  CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1738c609719bSwdenk		Machine Mode Register and Memory Periodic Timer
1739c609719bSwdenk		Prescaler definitions (SDRAM timing)
1740c609719bSwdenk
1741c609719bSwdenk- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1742c609719bSwdenk		enable I2C microcode relocation patch (MPC8xx);
1743c609719bSwdenk		define relocation offset in DPRAM [DSP2]
1744c609719bSwdenk
1745c609719bSwdenk- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1746c609719bSwdenk		enable SPI microcode relocation patch (MPC8xx);
1747c609719bSwdenk		define relocation offset in DPRAM [SCC4]
1748c609719bSwdenk
1749c609719bSwdenk- CFG_USE_OSCCLK:
1750c609719bSwdenk		Use OSCM clock mode on MBX8xx board. Be careful,
1751c609719bSwdenk		wrong setting might damage your board. Read
1752c609719bSwdenk		doc/README.MBX before setting this variable!
1753c609719bSwdenk
1754ea909b76Swdenk- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1755ea909b76Swdenk		Offset of the bootmode word in DPRAM used by post
1756ea909b76Swdenk		(Power On Self Tests). This definition overrides
1757ea909b76Swdenk		#define'd default value in commproc.h resp.
1758ea909b76Swdenk		cpm_8260.h.
1759ea909b76Swdenk
17605d232d0eSwdenk- CFG_PCI_SLV_MEM_LOCAL, CFG_PCI_SLV_MEM_BUS, CFG_PICMR0_MASK_ATTRIB,
17615d232d0eSwdenk  CFG_PCI_MSTR0_LOCAL, CFG_PCIMSK0_MASK, CFG_PCI_MSTR1_LOCAL,
17625d232d0eSwdenk  CFG_PCIMSK1_MASK, CFG_PCI_MSTR_MEM_LOCAL, CFG_PCI_MSTR_MEM_BUS,
17635d232d0eSwdenk  CFG_CPU_PCI_MEM_START, CFG_PCI_MSTR_MEM_SIZE, CFG_POCMR0_MASK_ATTRIB,
17645d232d0eSwdenk  CFG_PCI_MSTR_MEMIO_LOCAL, CFG_PCI_MSTR_MEMIO_BUS, CPU_PCI_MEMIO_START,
17655d232d0eSwdenk  CFG_PCI_MSTR_MEMIO_SIZE, CFG_POCMR1_MASK_ATTRIB, CFG_PCI_MSTR_IO_LOCAL,
17665d232d0eSwdenk  CFG_PCI_MSTR_IO_BUS, CFG_CPU_PCI_IO_START, CFG_PCI_MSTR_IO_SIZE,
17675d232d0eSwdenk  CFG_POCMR2_MASK_ATTRIB: (MPC826x only)
17685d232d0eSwdenk		Overrides the default PCI memory map in cpu/mpc8260/pci.c if set.
17695d232d0eSwdenk
1770c609719bSwdenkBuilding the Software:
1771c609719bSwdenk======================
1772c609719bSwdenk
1773c609719bSwdenkBuilding U-Boot has been tested in native PPC environments (on a
1774c609719bSwdenkPowerBook G3 running LinuxPPC 2000) and in cross environments
1775c609719bSwdenk(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1776c609719bSwdenkNetBSD 1.5 on x86).
1777c609719bSwdenk
1778c609719bSwdenkIf you are not using a native PPC environment, it is assumed that you
1779c609719bSwdenkhave the GNU cross compiling tools available in your path and named
1780c609719bSwdenkwith a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1781c609719bSwdenkyou are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1782c609719bSwdenkthe definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1783c609719bSwdenkchange it to:
1784c609719bSwdenk
1785c609719bSwdenk	CROSS_COMPILE = ppc_4xx-
1786c609719bSwdenk
1787c609719bSwdenk
1788c609719bSwdenkU-Boot is intended to be  simple  to  build.  After  installing  the
1789c609719bSwdenksources	 you must configure U-Boot for one specific board type. This
1790c609719bSwdenkis done by typing:
1791c609719bSwdenk
1792c609719bSwdenk	make NAME_config
1793c609719bSwdenk
1794c609719bSwdenkwhere "NAME_config" is the name of one of the existing
1795c609719bSwdenkconfigurations; the following names are supported:
1796c609719bSwdenk
1797c609719bSwdenk    ADCIOP_config	  GTH_config		TQM850L_config
1798c609719bSwdenk    ADS860_config	  IP860_config		TQM855L_config
1799c609719bSwdenk    AR405_config	  IVML24_config		TQM860L_config
1800c609719bSwdenk    CANBT_config	  IVMS8_config		WALNUT405_config
1801c609719bSwdenk    CPCI405_config	  LANTEC_config		cogent_common_config
1802c609719bSwdenk    CPCIISER4_config	  MBX_config		cogent_mpc8260_config
1803c609719bSwdenk    CU824_config	  MBX860T_config	cogent_mpc8xx_config
1804c609719bSwdenk    ESTEEM192E_config	  RPXlite_config	hermes_config
1805c609719bSwdenk    ETX094_config	  RPXsuper_config	hymod_config
1806c609719bSwdenk    FADS823_config	  SM850_config		lwmon_config
1807c609719bSwdenk    FADS850SAR_config	  SPD823TS_config	pcu_e_config
1808c609719bSwdenk    FADS860T_config	  SXNI855T_config	rsdproto_config
1809c609719bSwdenk    FPS850L_config	  Sandpoint8240_config	sbc8260_config
1810c609719bSwdenk    GENIETV_config	  TQM823L_config	PIP405_config
1811384ae025Swdenk    GEN860T_config	  EBONY_config		FPS860L_config
18127f70e853Swdenk    ELPT860_config	  cmi_mpc5xx_config	NETVIA_config
18132abbe075Swdenk    at91rm9200dk_config
1814c609719bSwdenk
1815c609719bSwdenkNote: for some board special configuration names may exist; check  if
1816c609719bSwdenk      additional  information is available from the board vendor; for
1817c609719bSwdenk      instance, the TQM8xxL systems run normally at 50 MHz and use  a
1818c609719bSwdenk      SCC  for	10baseT	 ethernet; there are also systems with 80 MHz
1819c609719bSwdenk      CPU clock, and an optional Fast Ethernet	module	is  available
1820c609719bSwdenk      for  CPU's  with FEC. You can select such additional "features"
1821c609719bSwdenk      when chosing the configuration, i. e.
1822c609719bSwdenk
1823c609719bSwdenk      make TQM860L_config
1824c609719bSwdenk	- will configure for a plain TQM860L, i. e. 50MHz, no FEC
1825c609719bSwdenk
1826c609719bSwdenk      make TQM860L_FEC_config
1827c609719bSwdenk	- will configure for a TQM860L at 50MHz with FEC for ethernet
1828c609719bSwdenk
1829c609719bSwdenk      make TQM860L_80MHz_config
1830c609719bSwdenk	- will configure for a TQM860L at 80 MHz, with normal 10baseT
1831c609719bSwdenk	  interface
1832c609719bSwdenk
1833c609719bSwdenk      make TQM860L_FEC_80MHz_config
1834c609719bSwdenk	- will configure for a TQM860L at 80 MHz with FEC for ethernet
1835c609719bSwdenk
1836c609719bSwdenk      make TQM823L_LCD_config
1837c609719bSwdenk	- will configure for a TQM823L with U-Boot console on LCD
1838c609719bSwdenk
1839c609719bSwdenk      make TQM823L_LCD_80MHz_config
1840c609719bSwdenk	- will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1841c609719bSwdenk
1842c609719bSwdenk      etc.
1843c609719bSwdenk
1844c609719bSwdenk
1845c609719bSwdenk
1846c609719bSwdenkFinally, type "make all", and you should get some working U-Boot
1847c609719bSwdenkimages ready for downlod to / installation on your system:
1848c609719bSwdenk
1849c609719bSwdenk- "u-boot.bin" is a raw binary image
1850c609719bSwdenk- "u-boot" is an image in ELF binary format
1851c609719bSwdenk- "u-boot.srec" is in Motorola S-Record format
1852c609719bSwdenk
1853c609719bSwdenk
1854c609719bSwdenkPlease be aware that the Makefiles assume you are using GNU make, so
1855c609719bSwdenkfor instance on NetBSD you might need to use "gmake" instead of
1856c609719bSwdenknative "make".
1857c609719bSwdenk
1858c609719bSwdenk
1859c609719bSwdenkIf the system board that you have is not listed, then you will need
1860c609719bSwdenkto port U-Boot to your hardware platform. To do this, follow these
1861c609719bSwdenksteps:
1862c609719bSwdenk
1863c609719bSwdenk1.  Add a new configuration option for your board to the toplevel
186485ec0bccSwdenk    "Makefile" and to the "MAKEALL" script, using the existing
186585ec0bccSwdenk    entries as examples. Note that here and at many other places
186685ec0bccSwdenk    boards and other names are listed alphabetically sorted. Please
186785ec0bccSwdenk    keep this order.
1868c609719bSwdenk2.  Create a new directory to hold your board specific code. Add any
186985ec0bccSwdenk    files you need. In your board directory, you will need at least
187085ec0bccSwdenk    the "Makefile", a "<board>.c", "flash.c" and "u-boot.lds".
187185ec0bccSwdenk3.  Create a new configuration file "include/configs/<board>.h" for
187285ec0bccSwdenk    your board
1873c609719bSwdenk3.  If you're porting U-Boot to a new CPU, then also create a new
1874c609719bSwdenk    directory to hold your CPU specific code. Add any files you need.
187585ec0bccSwdenk4.  Run "make <board>_config" with your new name.
1876c609719bSwdenk5.  Type "make", and you should get a working "u-boot.srec" file
1877c609719bSwdenk    to be installed on your target system.
187885ec0bccSwdenk6.  Debug and solve any problems that might arise.
1879c609719bSwdenk    [Of course, this last step is much harder than it sounds.]
1880c609719bSwdenk
1881c609719bSwdenk
1882c609719bSwdenkTesting of U-Boot Modifications, Ports to New Hardware, etc.:
1883c609719bSwdenk==============================================================
1884c609719bSwdenk
1885c609719bSwdenkIf you have modified U-Boot sources (for instance added a new	board
1886c609719bSwdenkor  support  for  new  devices,	 a new CPU, etc.) you are expected to
1887c609719bSwdenkprovide feedback to the other developers. The feedback normally takes
1888c609719bSwdenkthe form of a "patch", i. e. a context diff against a certain (latest
1889c609719bSwdenkofficial or latest in CVS) version of U-Boot sources.
1890c609719bSwdenk
1891c609719bSwdenkBut before you submit such a patch, please verify that	your  modifi-
1892c609719bSwdenkcation	did not break existing code. At least make sure that *ALL* of
1893c609719bSwdenkthe supported boards compile WITHOUT ANY compiler warnings. To do so,
1894c609719bSwdenkjust run the "MAKEALL" script, which will configure and build U-Boot
1895c609719bSwdenkfor ALL supported system. Be warned, this will take a while. You  can
1896c609719bSwdenkselect	which  (cross)	compiler  to use py passing a `CROSS_COMPILE'
1897c609719bSwdenkenvironment variable to the script, i. e. to use the cross tools from
1898c609719bSwdenkMontaVista's Hard Hat Linux you can type
1899c609719bSwdenk
1900c609719bSwdenk	CROSS_COMPILE=ppc_8xx- MAKEALL
1901c609719bSwdenk
1902c609719bSwdenkor to build on a native PowerPC system you can type
1903c609719bSwdenk
1904c609719bSwdenk	CROSS_COMPILE=' ' MAKEALL
1905c609719bSwdenk
1906c609719bSwdenkSee also "U-Boot Porting Guide" below.
1907c609719bSwdenk
1908c609719bSwdenk
1909c609719bSwdenk
1910c609719bSwdenkMonitor Commands - Overview:
1911c609719bSwdenk============================
1912c609719bSwdenk
1913c609719bSwdenkgo	- start application at address 'addr'
1914c609719bSwdenkrun	- run commands in an environment variable
1915c609719bSwdenkbootm	- boot application image from memory
1916c609719bSwdenkbootp	- boot image via network using BootP/TFTP protocol
1917c609719bSwdenktftpboot- boot image via network using TFTP protocol
1918c609719bSwdenk	       and env variables "ipaddr" and "serverip"
1919c609719bSwdenk	       (and eventually "gatewayip")
1920c609719bSwdenkrarpboot- boot image via network using RARP/TFTP protocol
1921c609719bSwdenkdiskboot- boot from IDE devicebootd   - boot default, i.e., run 'bootcmd'
1922c609719bSwdenkloads	- load S-Record file over serial line
1923c609719bSwdenkloadb	- load binary file over serial line (kermit mode)
1924c609719bSwdenkmd	- memory display
1925c609719bSwdenkmm	- memory modify (auto-incrementing)
1926c609719bSwdenknm	- memory modify (constant address)
1927c609719bSwdenkmw	- memory write (fill)
1928c609719bSwdenkcp	- memory copy
1929c609719bSwdenkcmp	- memory compare
1930c609719bSwdenkcrc32	- checksum calculation
1931c609719bSwdenkimd     - i2c memory display
1932c609719bSwdenkimm     - i2c memory modify (auto-incrementing)
1933c609719bSwdenkinm     - i2c memory modify (constant address)
1934c609719bSwdenkimw     - i2c memory write (fill)
1935c609719bSwdenkicrc32  - i2c checksum calculation
1936c609719bSwdenkiprobe  - probe to discover valid I2C chip addresses
1937c609719bSwdenkiloop   - infinite loop on address range
1938c609719bSwdenkisdram  - print SDRAM configuration information
1939c609719bSwdenksspi    - SPI utility commands
1940c609719bSwdenkbase	- print or set address offset
1941c609719bSwdenkprintenv- print environment variables
1942c609719bSwdenksetenv	- set environment variables
1943c609719bSwdenksaveenv - save environment variables to persistent storage
1944c609719bSwdenkprotect - enable or disable FLASH write protection
1945c609719bSwdenkerase	- erase FLASH memory
1946c609719bSwdenkflinfo	- print FLASH memory information
1947c609719bSwdenkbdinfo	- print Board Info structure
1948c609719bSwdenkiminfo	- print header information for application image
1949c609719bSwdenkconinfo - print console devices and informations
1950c609719bSwdenkide	- IDE sub-system
1951c609719bSwdenkloop	- infinite loop on address range
1952c609719bSwdenkmtest	- simple RAM test
1953c609719bSwdenkicache	- enable or disable instruction cache
1954c609719bSwdenkdcache	- enable or disable data cache
1955c609719bSwdenkreset	- Perform RESET of the CPU
1956c609719bSwdenkecho	- echo args to console
1957c609719bSwdenkversion - print monitor version
1958c609719bSwdenkhelp	- print online help
1959c609719bSwdenk?	- alias for 'help'
1960c609719bSwdenk
1961c609719bSwdenk
1962c609719bSwdenkMonitor Commands - Detailed Description:
1963c609719bSwdenk========================================
1964c609719bSwdenk
1965c609719bSwdenkTODO.
1966c609719bSwdenk
1967c609719bSwdenkFor now: just type "help <command>".
1968c609719bSwdenk
1969c609719bSwdenk
1970c609719bSwdenkEnvironment Variables:
1971c609719bSwdenk======================
1972c609719bSwdenk
1973c609719bSwdenkU-Boot supports user configuration using Environment Variables which
1974c609719bSwdenkcan be made persistent by saving to Flash memory.
1975c609719bSwdenk
1976c609719bSwdenkEnvironment Variables are set using "setenv", printed using
1977c609719bSwdenk"printenv", and saved to Flash using "saveenv". Using "setenv"
1978c609719bSwdenkwithout a value can be used to delete a variable from the
1979c609719bSwdenkenvironment. As long as you don't save the environment you are
1980c609719bSwdenkworking with an in-memory copy. In case the Flash area containing the
1981c609719bSwdenkenvironment is erased by accident, a default environment is provided.
1982c609719bSwdenk
1983c609719bSwdenkSome configuration options can be set using Environment Variables:
1984c609719bSwdenk
1985c609719bSwdenk  baudrate	- see CONFIG_BAUDRATE
1986c609719bSwdenk
1987c609719bSwdenk  bootdelay	- see CONFIG_BOOTDELAY
1988c609719bSwdenk
1989c609719bSwdenk  bootcmd	- see CONFIG_BOOTCOMMAND
1990c609719bSwdenk
1991c609719bSwdenk  bootargs	- Boot arguments when booting an RTOS image
1992c609719bSwdenk
1993c609719bSwdenk  bootfile	- Name of the image to load with TFTP
1994c609719bSwdenk
1995c609719bSwdenk  autoload	- if set to "no" (any string beginning with 'n'),
1996c609719bSwdenk		  "bootp" will just load perform a lookup of the
1997c609719bSwdenk		  configuration from the BOOTP server, but not try to
1998c609719bSwdenk		  load any image using TFTP
1999c609719bSwdenk
2000c609719bSwdenk  autostart	- if set to "yes", an image loaded using the "bootp",
2001c609719bSwdenk		  "rarpboot", "tftpboot" or "diskboot" commands will
2002c609719bSwdenk		  be automatically started (by internally calling
2003c609719bSwdenk		  "bootm")
2004c609719bSwdenk
20054a6fd34bSwdenk		  If set to "no", a standalone image passed to the
20064a6fd34bSwdenk		  "bootm" command will be copied to the load address
20074a6fd34bSwdenk		  (and eventually uncompressed), but NOT be started.
20084a6fd34bSwdenk		  This can be used to load and uncompress arbitrary
20094a6fd34bSwdenk		  data.
20104a6fd34bSwdenk
2011c609719bSwdenk  initrd_high	- restrict positioning of initrd images:
2012c609719bSwdenk		  If this variable is not set, initrd images will be
2013c609719bSwdenk		  copied to the highest possible address in RAM; this
2014c609719bSwdenk		  is usually what you want since it allows for
2015c609719bSwdenk		  maximum initrd size. If for some reason you want to
2016c609719bSwdenk		  make sure that the initrd image is loaded below the
2017c609719bSwdenk		  CFG_BOOTMAPSZ limit, you can set this environment
2018c609719bSwdenk		  variable to a value of "no" or "off" or "0".
2019c609719bSwdenk		  Alternatively, you can set it to a maximum upper
2020c609719bSwdenk		  address to use (U-Boot will still check that it
2021c609719bSwdenk		  does not overwrite the U-Boot stack and data).
2022c609719bSwdenk
2023c609719bSwdenk		  For instance, when you have a system with 16 MB
2024c609719bSwdenk		  RAM, and want to reseve 4 MB from use by Linux,
2025c609719bSwdenk		  you can do this by adding "mem=12M" to the value of
2026c609719bSwdenk		  the "bootargs" variable. However, now you must make
2027c609719bSwdenk		  sure, that the initrd image is placed in the first
2028c609719bSwdenk		  12 MB as well - this can be done with
2029c609719bSwdenk
2030c609719bSwdenk		  setenv initrd_high 00c00000
2031c609719bSwdenk
203238b99261Swdenk                  If you set initrd_high to 0xFFFFFFFF, this is an
203338b99261Swdenk                  indication to U-Boot that all addresses are legal
203438b99261Swdenk                  for the Linux kernel, including addresses in flash
203538b99261Swdenk                  memory. In this case U-Boot will NOT COPY the
203638b99261Swdenk                  ramdisk at all. This may be useful to reduce the
203738b99261Swdenk                  boot time on your system, but requires that this
203838b99261Swdenk                  feature is supported by your Linux kernel.
203938b99261Swdenk
2040c609719bSwdenk  ipaddr	- IP address; needed for tftpboot command
2041c609719bSwdenk
2042c609719bSwdenk  loadaddr	- Default load address for commands like "bootp",
2043dc7c9a1aSwdenk		  "rarpboot", "tftpboot", "loadb" or "diskboot"
2044c609719bSwdenk
2045c609719bSwdenk  loads_echo	- see CONFIG_LOADS_ECHO
2046c609719bSwdenk
2047c609719bSwdenk  serverip	- TFTP server IP address; needed for tftpboot command
2048c609719bSwdenk
2049c609719bSwdenk  bootretry	- see CONFIG_BOOT_RETRY_TIME
2050c609719bSwdenk
2051c609719bSwdenk  bootdelaykey	- see CONFIG_AUTOBOOT_DELAY_STR
2052c609719bSwdenk
2053c609719bSwdenk  bootstopkey	- see CONFIG_AUTOBOOT_STOP_STR
2054c609719bSwdenk
2055c609719bSwdenk
2056c609719bSwdenkThe following environment variables may be used and automatically
2057c609719bSwdenkupdated by the network boot commands ("bootp" and "rarpboot"),
2058c609719bSwdenkdepending the information provided by your boot server:
2059c609719bSwdenk
2060c609719bSwdenk  bootfile	- see above
2061c609719bSwdenk  dnsip		- IP address of your Domain Name Server
2062c609719bSwdenk  gatewayip	- IP address of the Gateway (Router) to use
2063c609719bSwdenk  hostname	- Target hostname
2064c609719bSwdenk  ipaddr	- see above
2065c609719bSwdenk  netmask	- Subnet Mask
2066c609719bSwdenk  rootpath	- Pathname of the root filesystem on the NFS server
2067c609719bSwdenk  serverip	- see above
2068c609719bSwdenk
2069c609719bSwdenk
2070c609719bSwdenkThere are two special Environment Variables:
2071c609719bSwdenk
2072c609719bSwdenk  serial#	- contains hardware identification information such
2073c609719bSwdenk		  as type string and/or serial number
2074c609719bSwdenk  ethaddr	- Ethernet address
2075c609719bSwdenk
2076c609719bSwdenkThese variables can be set only once (usually during manufacturing of
2077c609719bSwdenkthe board). U-Boot refuses to delete or overwrite these variables
2078c609719bSwdenkonce they have been set once.
2079c609719bSwdenk
2080c609719bSwdenk
2081c1551ea8SstroeseFurther special Environment Variables:
2082c1551ea8Sstroese
2083c1551ea8Sstroese  ver		- Contains the U-Boot version string as printed
2084c1551ea8Sstroese		  with the "version" command. This variable is
2085c1551ea8Sstroese		  readonly (see CONFIG_VERSION_VARIABLE).
2086c1551ea8Sstroese
2087c1551ea8Sstroese
2088c609719bSwdenkPlease note that changes to some configuration parameters may take
2089c609719bSwdenkonly effect after the next boot (yes, that's just like Windoze :-).
2090c609719bSwdenk
2091c609719bSwdenk
2092f07771ccSwdenkCommand Line Parsing:
2093f07771ccSwdenk=====================
2094f07771ccSwdenk
2095f07771ccSwdenkThere are two different command line parsers available  with  U-Boot:
2096f07771ccSwdenkthe old "simple" one, and the much more pwerful "hush" shell:
2097f07771ccSwdenk
2098f07771ccSwdenkOld, simple command line parser:
2099f07771ccSwdenk--------------------------------
2100f07771ccSwdenk
2101f07771ccSwdenk- supports environment variables (through setenv / saveenv commands)
2102f07771ccSwdenk- several commands on one line, separated by ';'
2103f07771ccSwdenk- variable substitution using "... $(name) ..." syntax
2104f07771ccSwdenk- special characters ('$', ';') can be escaped by prefixing with '\',
2105f07771ccSwdenk  for example:
2106f07771ccSwdenk	setenv bootcmd bootm \$(address)
2107f07771ccSwdenk- You can also escape text by enclosing in single apostrophes, for example:
2108f07771ccSwdenk	setenv addip 'setenv bootargs $bootargs ip=$ipaddr:$serverip:$gatewayip:$netmask:$hostname::off'
2109f07771ccSwdenk
2110f07771ccSwdenkHush shell:
2111f07771ccSwdenk-----------
2112f07771ccSwdenk
2113f07771ccSwdenk- similar to Bourne shell, with control structures like
2114f07771ccSwdenk  if...then...else...fi, for...do...done; while...do...done,
2115f07771ccSwdenk  until...do...done, ...
2116f07771ccSwdenk- supports environment ("global") variables (through setenv / saveenv
2117f07771ccSwdenk  commands) and local shell variables (through standard shell syntax
2118f07771ccSwdenk  "name=value"); only environment variables can be used with "run"
2119f07771ccSwdenk  command
2120f07771ccSwdenk
2121f07771ccSwdenkGeneral rules:
2122f07771ccSwdenk--------------
2123f07771ccSwdenk
2124f07771ccSwdenk(1) If a command line (or an environment variable executed by a "run"
2125f07771ccSwdenk    command) contains several commands separated by semicolon, and
2126f07771ccSwdenk    one of these commands fails, then the remaining commands will be
2127f07771ccSwdenk    executed anyway.
2128f07771ccSwdenk
2129f07771ccSwdenk(2) If you execute several variables with one call to run (i. e.
2130f07771ccSwdenk    calling run with a list af variables as arguments), any failing
2131f07771ccSwdenk    command will cause "run" to terminate, i. e. the remaining
2132f07771ccSwdenk    variables are not executed.
2133f07771ccSwdenk
2134c609719bSwdenkNote for Redundant Ethernet Interfaces:
2135c609719bSwdenk=======================================
2136c609719bSwdenk
2137c609719bSwdenkSome boards come with redundand ethernet interfaces; U-Boot supports
2138c609719bSwdenksuch configurations and is capable of automatic selection of a
2139c609719bSwdenk"working" interface when needed. MAC assignemnt works as follows:
2140c609719bSwdenk
2141c609719bSwdenkNetwork interfaces are numbered eth0, eth1, eth2, ... Corresponding
2142c609719bSwdenkMAC addresses can be stored in the environment as "ethaddr" (=>eth0),
2143c609719bSwdenk"eth1addr" (=>eth1), "eth2addr", ...
2144c609719bSwdenk
2145c609719bSwdenkIf the network interface stores some valid MAC address (for instance
2146c609719bSwdenkin SROM), this is used as default address if there is NO correspon-
2147c609719bSwdenkding setting in the environment; if the corresponding environment
2148c609719bSwdenkvariable is set, this overrides the settings in the card; that means:
2149c609719bSwdenk
2150c609719bSwdenko If the SROM has a valid MAC address, and there is no address in the
2151c609719bSwdenk  environment, the SROM's address is used.
2152c609719bSwdenk
2153c609719bSwdenko If there is no valid address in the SROM, and a definition in the
2154c609719bSwdenk  environment exists, then the value from the environment variable is
2155c609719bSwdenk  used.
2156c609719bSwdenk
2157c609719bSwdenko If both the SROM and the environment contain a MAC address, and
2158c609719bSwdenk  both addresses are the same, this MAC address is used.
2159c609719bSwdenk
2160c609719bSwdenko If both the SROM and the environment contain a MAC address, and the
2161c609719bSwdenk  addresses differ, the value from the environment is used and a
2162c609719bSwdenk  warning is printed.
2163c609719bSwdenk
2164c609719bSwdenko If neither SROM nor the environment contain a MAC address, an error
2165c609719bSwdenk  is raised.
2166c609719bSwdenk
2167c609719bSwdenk
2168c609719bSwdenk
2169c609719bSwdenkImage Formats:
2170c609719bSwdenk==============
2171c609719bSwdenk
2172c609719bSwdenkThe "boot" commands of this monitor operate on "image" files which
2173c609719bSwdenkcan be basicly anything, preceeded by a special header; see the
2174c609719bSwdenkdefinitions in include/image.h for details; basicly, the header
2175c609719bSwdenkdefines the following image properties:
2176c609719bSwdenk
2177c609719bSwdenk* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2178c609719bSwdenk  4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
21797f70e853Swdenk  LynxOS, pSOS, QNX, RTEMS, ARTOS;
21807f70e853Swdenk  Currently supported: Linux, NetBSD, VxWorks, QNX, RTEMS, ARTOS).
2181c609719bSwdenk* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2182c609719bSwdenk  IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2183c609719bSwdenk  Currently supported: PowerPC).
2184c609719bSwdenk* Compression Type (Provisions for uncompressed, gzip, bzip2;
2185c609719bSwdenk  Currently supported: uncompressed, gzip).
2186c609719bSwdenk* Load Address
2187c609719bSwdenk* Entry Point
2188c609719bSwdenk* Image Name
2189c609719bSwdenk* Image Timestamp
2190c609719bSwdenk
2191c609719bSwdenkThe header is marked by a special Magic Number, and both the header
2192c609719bSwdenkand the data portions of the image are secured against corruption by
2193c609719bSwdenkCRC32 checksums.
2194c609719bSwdenk
2195c609719bSwdenk
2196c609719bSwdenkLinux Support:
2197c609719bSwdenk==============
2198c609719bSwdenk
2199c609719bSwdenkAlthough U-Boot should support any OS or standalone application
2200c609719bSwdenkeasily, Linux has always been in the focus during the design of
2201c609719bSwdenkU-Boot.
2202c609719bSwdenk
2203c609719bSwdenkU-Boot includes many features that so far have been part of some
2204c609719bSwdenkspecial "boot loader" code within the Linux kernel. Also, any
2205c609719bSwdenk"initrd" images to be used are no longer part of one big Linux image;
2206c609719bSwdenkinstead, kernel and "initrd" are separate images. This implementation
2207c609719bSwdenkserves serveral purposes:
2208c609719bSwdenk
2209c609719bSwdenk- the same features can be used for other OS or standalone
2210c609719bSwdenk  applications (for instance: using compressed images to reduce the
2211c609719bSwdenk  Flash memory footprint)
2212c609719bSwdenk
2213c609719bSwdenk- it becomes much easier to port new Linux kernel versions because
2214c609719bSwdenk  lots of low-level, hardware dependend stuff are done by U-Boot
2215c609719bSwdenk
2216c609719bSwdenk- the same Linux kernel image can now be used with different "initrd"
2217c609719bSwdenk  images; of course this also means that different kernel images can
2218c609719bSwdenk  be run with the same "initrd". This makes testing easier (you don't
2219c609719bSwdenk  have to build a new "zImage.initrd" Linux image when you just
2220c609719bSwdenk  change a file in your "initrd"). Also, a field-upgrade of the
2221c609719bSwdenk  software is easier now.
2222c609719bSwdenk
2223c609719bSwdenk
2224c609719bSwdenkLinux HOWTO:
2225c609719bSwdenk============
2226c609719bSwdenk
2227c609719bSwdenkPorting Linux to U-Boot based systems:
2228c609719bSwdenk---------------------------------------
2229c609719bSwdenk
2230c609719bSwdenkU-Boot cannot save you from doing all the necessary modifications to
2231c609719bSwdenkconfigure the Linux device drivers for use with your target hardware
2232c609719bSwdenk(no, we don't intend to provide a full virtual machine interface to
2233c609719bSwdenkLinux :-).
2234c609719bSwdenk
2235c609719bSwdenkBut now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2236c609719bSwdenk
2237c609719bSwdenkJust make sure your machine specific header file (for instance
2238c609719bSwdenkinclude/asm-ppc/tqm8xx.h) includes the same definition of the Board
2239c609719bSwdenkInformation structure as we define in include/u-boot.h, and make
2240c609719bSwdenksure that your definition of IMAP_ADDR uses the same value as your
2241c609719bSwdenkU-Boot configuration in CFG_IMMR.
2242c609719bSwdenk
2243c609719bSwdenk
2244c609719bSwdenkConfiguring the Linux kernel:
2245c609719bSwdenk-----------------------------
2246c609719bSwdenk
2247c609719bSwdenkNo specific requirements for U-Boot. Make sure you have some root
2248c609719bSwdenkdevice (initial ramdisk, NFS) for your target system.
2249c609719bSwdenk
2250c609719bSwdenk
2251c609719bSwdenkBuilding a Linux Image:
2252c609719bSwdenk-----------------------
2253c609719bSwdenk
225424ee89b9SwdenkWith U-Boot, "normal" build targets like "zImage" or "bzImage" are
225524ee89b9Swdenknot used. If you use recent kernel source, a new build target
225624ee89b9Swdenk"uImage" will exist which automatically builds an image usable by
225724ee89b9SwdenkU-Boot. Most older kernels also have support for a "pImage" target,
225824ee89b9Swdenkwhich was introduced for our predecessor project PPCBoot and uses a
225924ee89b9Swdenk100% compatible format.
2260c609719bSwdenk
2261c609719bSwdenkExample:
2262c609719bSwdenk
2263c609719bSwdenk	make TQM850L_config
2264c609719bSwdenk	make oldconfig
2265c609719bSwdenk	make dep
226624ee89b9Swdenk	make uImage
2267c609719bSwdenk
226824ee89b9SwdenkThe "uImage" build target uses a special tool (in 'tools/mkimage') to
226924ee89b9Swdenkencapsulate a compressed Linux kernel image with header  information,
227024ee89b9SwdenkCRC32 checksum etc. for use with U-Boot. This is what we are doing:
2271c609719bSwdenk
227224ee89b9Swdenk* build a standard "vmlinux" kernel image (in ELF binary format):
227324ee89b9Swdenk
227424ee89b9Swdenk* convert the kernel into a raw binary image:
227524ee89b9Swdenk
227624ee89b9Swdenk	${CROSS_COMPILE}-objcopy -O binary \
227724ee89b9Swdenk				 -R .note -R .comment \
227824ee89b9Swdenk				 -S vmlinux linux.bin
227924ee89b9Swdenk
228024ee89b9Swdenk* compress the binary image:
228124ee89b9Swdenk
228224ee89b9Swdenk	gzip -9 linux.bin
228324ee89b9Swdenk
228424ee89b9Swdenk* package compressed binary image for U-Boot:
228524ee89b9Swdenk
228624ee89b9Swdenk	mkimage -A ppc -O linux -T kernel -C gzip \
228724ee89b9Swdenk		-a 0 -e 0 -n "Linux Kernel Image" \
228824ee89b9Swdenk		-d linux.bin.gz uImage
228924ee89b9Swdenk
229024ee89b9Swdenk
229124ee89b9SwdenkThe "mkimage" tool can also be used to create ramdisk images for use
229224ee89b9Swdenkwith U-Boot, either separated from the Linux kernel image, or
229324ee89b9Swdenkcombined into one file. "mkimage" encapsulates the images with a 64
229424ee89b9Swdenkbyte header containing information about target architecture,
229524ee89b9Swdenkoperating system, image type, compression method, entry points, time
229624ee89b9Swdenkstamp, CRC32 checksums, etc.
229724ee89b9Swdenk
229824ee89b9Swdenk"mkimage" can be called in two ways: to verify existing images and
229924ee89b9Swdenkprint the header information, or to build new images.
2300c609719bSwdenk
2301c609719bSwdenkIn the first form (with "-l" option) mkimage lists the information
2302c609719bSwdenkcontained in the header of an existing U-Boot image; this includes
2303c609719bSwdenkchecksum verification:
2304c609719bSwdenk
2305c609719bSwdenk	tools/mkimage -l image
2306c609719bSwdenk	  -l ==> list image header information
2307c609719bSwdenk
2308c609719bSwdenkThe second form (with "-d" option) is used to build a U-Boot image
2309c609719bSwdenkfrom a "data file" which is used as image payload:
2310c609719bSwdenk
2311c609719bSwdenk	tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2312c609719bSwdenk		      -n name -d data_file image
2313c609719bSwdenk	  -A ==> set architecture to 'arch'
2314c609719bSwdenk	  -O ==> set operating system to 'os'
2315c609719bSwdenk	  -T ==> set image type to 'type'
2316c609719bSwdenk	  -C ==> set compression type 'comp'
2317c609719bSwdenk	  -a ==> set load address to 'addr' (hex)
2318c609719bSwdenk	  -e ==> set entry point to 'ep' (hex)
2319c609719bSwdenk	  -n ==> set image name to 'name'
2320c609719bSwdenk	  -d ==> use image data from 'datafile'
2321c609719bSwdenk
2322c609719bSwdenkRight now, all Linux kernels use the same load address	(0x00000000),
2323c609719bSwdenkbut the entry point address depends on the kernel version:
2324c609719bSwdenk
2325c609719bSwdenk- 2.2.x kernels have the entry point at 0x0000000C,
232624ee89b9Swdenk- 2.3.x and later kernels have the entry point at 0x00000000.
2327c609719bSwdenk
2328c609719bSwdenkSo a typical call to build a U-Boot image would read:
2329c609719bSwdenk
233024ee89b9Swdenk	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
233124ee89b9Swdenk	> -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
233224ee89b9Swdenk	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
233324ee89b9Swdenk	> examples/uImage.TQM850L
233424ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2335c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2336c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2337c609719bSwdenk	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2338c609719bSwdenk	Load Address: 0x00000000
233924ee89b9Swdenk	Entry Point:  0x00000000
2340c609719bSwdenk
2341c609719bSwdenkTo verify the contents of the image (or check for corruption):
2342c609719bSwdenk
234324ee89b9Swdenk	-> tools/mkimage -l examples/uImage.TQM850L
234424ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2345c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2346c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2347c609719bSwdenk	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2348c609719bSwdenk	Load Address: 0x00000000
234924ee89b9Swdenk	Entry Point:  0x00000000
2350c609719bSwdenk
2351c609719bSwdenkNOTE: for embedded systems where boot time is critical you can trade
2352c609719bSwdenkspeed for memory and install an UNCOMPRESSED image instead: this
2353c609719bSwdenkneeds more space in Flash, but boots much faster since it does not
2354c609719bSwdenkneed to be uncompressed:
2355c609719bSwdenk
235624ee89b9Swdenk	-> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
235724ee89b9Swdenk	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
235824ee89b9Swdenk	> -A ppc -O linux -T kernel -C none -a 0 -e 0 \
235924ee89b9Swdenk	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
236024ee89b9Swdenk	> examples/uImage.TQM850L-uncompressed
236124ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2362c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2363c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (uncompressed)
2364c609719bSwdenk	Data Size:    792160 Bytes = 773.59 kB = 0.76 MB
2365c609719bSwdenk	Load Address: 0x00000000
236624ee89b9Swdenk	Entry Point:  0x00000000
2367c609719bSwdenk
2368c609719bSwdenk
2369c609719bSwdenkSimilar you can build U-Boot images from a 'ramdisk.image.gz' file
2370c609719bSwdenkwhen your kernel is intended to use an initial ramdisk:
2371c609719bSwdenk
2372c609719bSwdenk	-> tools/mkimage -n 'Simple Ramdisk Image' \
2373c609719bSwdenk	> -A ppc -O linux -T ramdisk -C gzip \
2374c609719bSwdenk	> -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2375c609719bSwdenk	Image Name:   Simple Ramdisk Image
2376c609719bSwdenk	Created:      Wed Jan 12 14:01:50 2000
2377c609719bSwdenk	Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)
2378c609719bSwdenk	Data Size:    566530 Bytes = 553.25 kB = 0.54 MB
2379c609719bSwdenk	Load Address: 0x00000000
2380c609719bSwdenk	Entry Point:  0x00000000
2381c609719bSwdenk
2382c609719bSwdenk
2383c609719bSwdenkInstalling a Linux Image:
2384c609719bSwdenk-------------------------
2385c609719bSwdenk
2386c609719bSwdenkTo downloading a U-Boot image over the serial (console) interface,
2387c609719bSwdenkyou must convert the image to S-Record format:
2388c609719bSwdenk
2389c609719bSwdenk	objcopy -I binary -O srec examples/image examples/image.srec
2390c609719bSwdenk
2391c609719bSwdenkThe 'objcopy' does not understand the information in the U-Boot
2392c609719bSwdenkimage header, so the resulting S-Record file will be relative to
2393c609719bSwdenkaddress 0x00000000. To load it to a given address, you need to
2394c609719bSwdenkspecify the target address as 'offset' parameter with the 'loads'
2395c609719bSwdenkcommand.
2396c609719bSwdenk
2397c609719bSwdenkExample: install the image to address 0x40100000 (which on the
2398c609719bSwdenkTQM8xxL is in the first Flash bank):
2399c609719bSwdenk
2400c609719bSwdenk	=> erase 40100000 401FFFFF
2401c609719bSwdenk
2402c609719bSwdenk	.......... done
2403c609719bSwdenk	Erased 8 sectors
2404c609719bSwdenk
2405c609719bSwdenk	=> loads 40100000
2406c609719bSwdenk	## Ready for S-Record download ...
2407c609719bSwdenk	~>examples/image.srec
2408c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2409c609719bSwdenk	...
2410c609719bSwdenk	15989 15990 15991 15992
2411c609719bSwdenk	[file transfer complete]
2412c609719bSwdenk	[connected]
2413c609719bSwdenk	## Start Addr = 0x00000000
2414c609719bSwdenk
2415c609719bSwdenk
2416c609719bSwdenkYou can check the success of the download using the 'iminfo' command;
2417c609719bSwdenkthis includes a checksum verification so you  can  be  sure  no	 data
2418c609719bSwdenkcorruption happened:
2419c609719bSwdenk
2420c609719bSwdenk	=> imi 40100000
2421c609719bSwdenk
2422c609719bSwdenk	## Checking Image at 40100000 ...
2423c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2424c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2425c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2426c609719bSwdenk	   Load Address: 00000000
2427c609719bSwdenk	   Entry Point:	 0000000c
2428c609719bSwdenk	   Verifying Checksum ... OK
2429c609719bSwdenk
2430c609719bSwdenk
2431c609719bSwdenk
2432c609719bSwdenkBoot Linux:
2433c609719bSwdenk-----------
2434c609719bSwdenk
2435c609719bSwdenkThe "bootm" command is used to boot an application that is stored in
2436c609719bSwdenkmemory (RAM or Flash). In case of a Linux kernel image, the contents
2437c609719bSwdenkof the "bootargs" environment variable is passed to the kernel as
2438c609719bSwdenkparameters. You can check and modify this variable using the
2439c609719bSwdenk"printenv" and "setenv" commands:
2440c609719bSwdenk
2441c609719bSwdenk
2442c609719bSwdenk	=> printenv bootargs
2443c609719bSwdenk	bootargs=root=/dev/ram
2444c609719bSwdenk
2445c609719bSwdenk	=> setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2446c609719bSwdenk
2447c609719bSwdenk	=> printenv bootargs
2448c609719bSwdenk	bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2449c609719bSwdenk
2450c609719bSwdenk	=> bootm 40020000
2451c609719bSwdenk	## Booting Linux kernel at 40020000 ...
2452c609719bSwdenk	   Image Name:	 2.2.13 for NFS on TQM850L
2453c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2454c609719bSwdenk	   Data Size:	 381681 Bytes = 372 kB = 0 MB
2455c609719bSwdenk	   Load Address: 00000000
2456c609719bSwdenk	   Entry Point:	 0000000c
2457c609719bSwdenk	   Verifying Checksum ... OK
2458c609719bSwdenk	   Uncompressing Kernel Image ... OK
2459c609719bSwdenk	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
2460c609719bSwdenk	Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2461c609719bSwdenk	time_init: decrementer frequency = 187500000/60
2462c609719bSwdenk	Calibrating delay loop... 49.77 BogoMIPS
2463c609719bSwdenk	Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2464c609719bSwdenk	...
2465c609719bSwdenk
2466c609719bSwdenkIf you want to boot a Linux kernel with initial ram disk, you pass
2467c609719bSwdenkthe memory addreses of both the kernel and the initrd image (PPBCOOT
2468c609719bSwdenkformat!) to the "bootm" command:
2469c609719bSwdenk
2470c609719bSwdenk	=> imi 40100000 40200000
2471c609719bSwdenk
2472c609719bSwdenk	## Checking Image at 40100000 ...
2473c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2474c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2475c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2476c609719bSwdenk	   Load Address: 00000000
2477c609719bSwdenk	   Entry Point:	 0000000c
2478c609719bSwdenk	   Verifying Checksum ... OK
2479c609719bSwdenk
2480c609719bSwdenk	## Checking Image at 40200000 ...
2481c609719bSwdenk	   Image Name:	 Simple Ramdisk Image
2482c609719bSwdenk	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2483c609719bSwdenk	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2484c609719bSwdenk	   Load Address: 00000000
2485c609719bSwdenk	   Entry Point:	 00000000
2486c609719bSwdenk	   Verifying Checksum ... OK
2487c609719bSwdenk
2488c609719bSwdenk	=> bootm 40100000 40200000
2489c609719bSwdenk	## Booting Linux kernel at 40100000 ...
2490c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2491c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2492c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2493c609719bSwdenk	   Load Address: 00000000
2494c609719bSwdenk	   Entry Point:	 0000000c
2495c609719bSwdenk	   Verifying Checksum ... OK
2496c609719bSwdenk	   Uncompressing Kernel Image ... OK
2497c609719bSwdenk	## Loading RAMDisk Image at 40200000 ...
2498c609719bSwdenk	   Image Name:	 Simple Ramdisk Image
2499c609719bSwdenk	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2500c609719bSwdenk	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2501c609719bSwdenk	   Load Address: 00000000
2502c609719bSwdenk	   Entry Point:	 00000000
2503c609719bSwdenk	   Verifying Checksum ... OK
2504c609719bSwdenk	   Loading Ramdisk ... OK
2505c609719bSwdenk	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
2506c609719bSwdenk	Boot arguments: root=/dev/ram
2507c609719bSwdenk	time_init: decrementer frequency = 187500000/60
2508c609719bSwdenk	Calibrating delay loop... 49.77 BogoMIPS
2509c609719bSwdenk	...
2510c609719bSwdenk	RAMDISK: Compressed image found at block 0
2511c609719bSwdenk	VFS: Mounted root (ext2 filesystem).
2512c609719bSwdenk
2513c609719bSwdenk	bash#
2514c609719bSwdenk
25156069ff26SwdenkMore About U-Boot Image Types:
25166069ff26Swdenk------------------------------
25176069ff26Swdenk
25186069ff26SwdenkU-Boot supports the following image types:
25196069ff26Swdenk
25206069ff26Swdenk   "Standalone Programs" are directly runnable in the environment
25216069ff26Swdenk  	provided by U-Boot; it is expected that (if they behave
25226069ff26Swdenk  	well) you can continue to work in U-Boot after return from
25236069ff26Swdenk  	the Standalone Program.
25246069ff26Swdenk   "OS Kernel Images" are usually images of some Embedded OS which
25256069ff26Swdenk  	will take over control completely. Usually these programs
25266069ff26Swdenk  	will install their own set of exception handlers, device
25276069ff26Swdenk  	drivers, set up the MMU, etc. - this means, that you cannot
25286069ff26Swdenk  	expect to re-enter U-Boot except by resetting the CPU.
25296069ff26Swdenk   "RAMDisk Images" are more or less just data blocks, and their
25306069ff26Swdenk  	parameters (address, size) are passed to an OS kernel that is
25316069ff26Swdenk  	being started.
25326069ff26Swdenk   "Multi-File Images" contain several images, typically an OS
25336069ff26Swdenk  	(Linux) kernel image and one or more data images like
25346069ff26Swdenk  	RAMDisks. This construct is useful for instance when you want
25356069ff26Swdenk  	to boot over the network using BOOTP etc., where the boot
25366069ff26Swdenk  	server provides just a single image file, but you want to get
25376069ff26Swdenk  	for instance an OS kernel and a RAMDisk image.
25386069ff26Swdenk
25396069ff26Swdenk  	"Multi-File Images" start with a list of image sizes, each
25406069ff26Swdenk  	image size (in bytes) specified by an "uint32_t" in network
25416069ff26Swdenk  	byte order. This list is terminated by an "(uint32_t)0".
25426069ff26Swdenk  	Immediately after the terminating 0 follow the images, one by
25436069ff26Swdenk  	one, all aligned on "uint32_t" boundaries (size rounded up to
25446069ff26Swdenk  	a multiple of 4 bytes).
25456069ff26Swdenk
25466069ff26Swdenk   "Firmware Images" are binary images containing firmware (like
25476069ff26Swdenk  	U-Boot or FPGA images) which usually will be programmed to
25486069ff26Swdenk  	flash memory.
25496069ff26Swdenk
25506069ff26Swdenk   "Script files" are command sequences that will be executed by
25516069ff26Swdenk  	U-Boot's command interpreter; this feature is especially
25526069ff26Swdenk  	useful when you configure U-Boot to use a real shell (hush)
25536069ff26Swdenk  	as command interpreter.
25546069ff26Swdenk
2555c609719bSwdenk
2556c609719bSwdenkStandalone HOWTO:
2557c609719bSwdenk=================
2558c609719bSwdenk
2559c609719bSwdenkOne of the features of U-Boot is that you can dynamically load and
2560c609719bSwdenkrun "standalone" applications, which can use some resources of
2561c609719bSwdenkU-Boot like console I/O functions or interrupt services.
2562c609719bSwdenk
2563c609719bSwdenkTwo simple examples are included with the sources:
2564c609719bSwdenk
2565c609719bSwdenk"Hello World" Demo:
2566c609719bSwdenk-------------------
2567c609719bSwdenk
2568c609719bSwdenk'examples/hello_world.c' contains a small "Hello World" Demo
2569c609719bSwdenkapplication; it is automatically compiled when you build U-Boot.
2570c609719bSwdenkIt's configured to run at address 0x00040004, so you can play with it
2571c609719bSwdenklike that:
2572c609719bSwdenk
2573c609719bSwdenk	=> loads
2574c609719bSwdenk	## Ready for S-Record download ...
2575c609719bSwdenk	~>examples/hello_world.srec
2576c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 ...
2577c609719bSwdenk	[file transfer complete]
2578c609719bSwdenk	[connected]
2579c609719bSwdenk	## Start Addr = 0x00040004
2580c609719bSwdenk
2581c609719bSwdenk	=> go 40004 Hello World! This is a test.
2582c609719bSwdenk	## Starting application at 0x00040004 ...
2583c609719bSwdenk	Hello World
2584c609719bSwdenk	argc = 7
2585c609719bSwdenk	argv[0] = "40004"
2586c609719bSwdenk	argv[1] = "Hello"
2587c609719bSwdenk	argv[2] = "World!"
2588c609719bSwdenk	argv[3] = "This"
2589c609719bSwdenk	argv[4] = "is"
2590c609719bSwdenk	argv[5] = "a"
2591c609719bSwdenk	argv[6] = "test."
2592c609719bSwdenk	argv[7] = "<NULL>"
2593c609719bSwdenk	Hit any key to exit ...
2594c609719bSwdenk
2595c609719bSwdenk	## Application terminated, rc = 0x0
2596c609719bSwdenk
2597c609719bSwdenkAnother example, which demonstrates how to register a CPM interrupt
2598c609719bSwdenkhandler with the U-Boot code, can be found in 'examples/timer.c'.
2599c609719bSwdenkHere, a CPM timer is set up to generate an interrupt every second.
2600c609719bSwdenkThe interrupt service routine is trivial, just printing a '.'
2601c609719bSwdenkcharacter, but this is just a demo program. The application can be
2602c609719bSwdenkcontrolled by the following keys:
2603c609719bSwdenk
2604c609719bSwdenk	? - print current values og the CPM Timer registers
2605c609719bSwdenk	b - enable interrupts and start timer
2606c609719bSwdenk	e - stop timer and disable interrupts
2607c609719bSwdenk	q - quit application
2608c609719bSwdenk
2609c609719bSwdenk	=> loads
2610c609719bSwdenk	## Ready for S-Record download ...
2611c609719bSwdenk	~>examples/timer.srec
2612c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 ...
2613c609719bSwdenk	[file transfer complete]
2614c609719bSwdenk	[connected]
2615c609719bSwdenk	## Start Addr = 0x00040004
2616c609719bSwdenk
2617c609719bSwdenk	=> go 40004
2618c609719bSwdenk	## Starting application at 0x00040004 ...
2619c609719bSwdenk	TIMERS=0xfff00980
2620c609719bSwdenk	Using timer 1
2621c609719bSwdenk	  tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2622c609719bSwdenk
2623c609719bSwdenkHit 'b':
2624c609719bSwdenk	[q, b, e, ?] Set interval 1000000 us
2625c609719bSwdenk	Enabling timer
2626c609719bSwdenkHit '?':
2627c609719bSwdenk	[q, b, e, ?] ........
2628c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2629c609719bSwdenkHit '?':
2630c609719bSwdenk	[q, b, e, ?] .
2631c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2632c609719bSwdenkHit '?':
2633c609719bSwdenk	[q, b, e, ?] .
2634c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2635c609719bSwdenkHit '?':
2636c609719bSwdenk	[q, b, e, ?] .
2637c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2638c609719bSwdenkHit 'e':
2639c609719bSwdenk	[q, b, e, ?] ...Stopping timer
2640c609719bSwdenkHit 'q':
2641c609719bSwdenk	[q, b, e, ?] ## Application terminated, rc = 0x0
2642c609719bSwdenk
2643c609719bSwdenk
264485ec0bccSwdenk
264585ec0bccSwdenkMinicom warning:
264685ec0bccSwdenk================
264785ec0bccSwdenk
264885ec0bccSwdenkOver time, many people have reported problems when trying to used the
264985ec0bccSwdenk"minicom" terminal emulation program for serial download. I (wd)
265085ec0bccSwdenkconsider minicom to be broken, and recommend not to use it. Under
2651f07771ccSwdenkUnix, I recommend to use C-Kermit for general purpose use (and
265285ec0bccSwdenkespecially for kermit binary protocol download ("loadb" command), and
265385ec0bccSwdenkuse "cu" for S-Record download ("loads" command).
265485ec0bccSwdenk
265552f52c14SwdenkNevertheless, if you absolutely want to use it try adding this
265652f52c14Swdenkconfiguration to your "File transfer protocols" section:
265752f52c14Swdenk
265852f52c14Swdenk	   Name    Program                      Name U/D FullScr IO-Red. Multi
265952f52c14Swdenk	X  kermit  /usr/bin/kermit -i -l %l -s   Y    U    Y       N      N
266052f52c14Swdenk	Y  kermit  /usr/bin/kermit -i -l %l -r   N    D    Y       N      N
266152f52c14Swdenk
266252f52c14Swdenk
2663c609719bSwdenkNetBSD Notes:
2664c609719bSwdenk=============
2665c609719bSwdenk
2666c609719bSwdenkStarting at version 0.9.2, U-Boot supports NetBSD both as host
2667c609719bSwdenk(build U-Boot) and target system (boots NetBSD/mpc8xx).
2668c609719bSwdenk
2669c609719bSwdenkBuilding requires a cross environment; it is known to work on
2670c609719bSwdenkNetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2671c609719bSwdenkneed gmake since the Makefiles are not compatible with BSD make).
2672c609719bSwdenkNote that the cross-powerpc package does not install include files;
2673c609719bSwdenkattempting to build U-Boot will fail because <machine/ansi.h> is
2674c609719bSwdenkmissing.  This file has to be installed and patched manually:
2675c609719bSwdenk
2676c609719bSwdenk	# cd /usr/pkg/cross/powerpc-netbsd/include
2677c609719bSwdenk	# mkdir powerpc
2678c609719bSwdenk	# ln -s powerpc machine
2679c609719bSwdenk	# cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2680c609719bSwdenk	# ${EDIT} powerpc/ansi.h	## must remove __va_list, _BSD_VA_LIST
2681c609719bSwdenk
2682c609719bSwdenkNative builds *don't* work due to incompatibilities between native
2683c609719bSwdenkand U-Boot include files.
2684c609719bSwdenk
2685c609719bSwdenkBooting assumes that (the first part of) the image booted is a
2686c609719bSwdenkstage-2 loader which in turn loads and then invokes the kernel
2687c609719bSwdenkproper. Loader sources will eventually appear in the NetBSD source
2688c609719bSwdenktree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2689c609719bSwdenkmeantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2690c609719bSwdenkdetails.
2691c609719bSwdenk
2692c609719bSwdenk
2693c609719bSwdenkImplementation Internals:
2694c609719bSwdenk=========================
2695c609719bSwdenk
2696c609719bSwdenkThe following is not intended to be a complete description of every
2697c609719bSwdenkimplementation detail. However, it should help to understand the
2698c609719bSwdenkinner workings of U-Boot and make it easier to port it to custom
2699c609719bSwdenkhardware.
2700c609719bSwdenk
2701c609719bSwdenk
2702c609719bSwdenkInitial Stack, Global Data:
2703c609719bSwdenk---------------------------
2704c609719bSwdenk
2705c609719bSwdenkThe implementation of U-Boot is complicated by the fact that U-Boot
2706c609719bSwdenkstarts running out of ROM (flash memory), usually without access to
2707c609719bSwdenksystem RAM (because the memory controller is not initialized yet).
2708c609719bSwdenkThis means that we don't have writable Data or BSS segments, and BSS
2709c609719bSwdenkis not initialized as zero. To be able to get a C environment working
2710c609719bSwdenkat all, we have to allocate at least a minimal stack. Implementation
2711c609719bSwdenkoptions for this are defined and restricted by the CPU used: Some CPU
2712c609719bSwdenkmodels provide on-chip memory (like the IMMR area on MPC8xx and
2713c609719bSwdenkMPC826x processors), on others (parts of) the data cache can be
2714c609719bSwdenklocked as (mis-) used as memory, etc.
2715c609719bSwdenk
271643d9616cSwdenk	Chris Hallinan posted a good summy of  these  issues  to  the
271743d9616cSwdenk	u-boot-users mailing list:
271843d9616cSwdenk
271943d9616cSwdenk	Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
272043d9616cSwdenk	From: "Chris Hallinan" <clh@net1plus.com>
272143d9616cSwdenk	Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
272243d9616cSwdenk	...
272343d9616cSwdenk
272443d9616cSwdenk	Correct me if I'm wrong, folks, but the way I understand it
272543d9616cSwdenk	is this: Using DCACHE as initial RAM for Stack, etc, does not
272643d9616cSwdenk	require any physical RAM backing up the cache. The cleverness
272743d9616cSwdenk	is that the cache is being used as a temporary supply of
272843d9616cSwdenk	necessary storage before the SDRAM controller is setup. It's
272943d9616cSwdenk	beyond the scope of this list to expain the details, but you
273043d9616cSwdenk	can see how this works by studying the cache architecture and
273143d9616cSwdenk	operation in the architecture and processor-specific manuals.
273243d9616cSwdenk
273343d9616cSwdenk	OCM is On Chip Memory, which I believe the 405GP has 4K. It
273443d9616cSwdenk	is another option for the system designer to use as an
273543d9616cSwdenk	initial stack/ram area prior to SDRAM being available. Either
273643d9616cSwdenk	option should work for you. Using CS 4 should be fine if your
273743d9616cSwdenk	board designers haven't used it for something that would
273843d9616cSwdenk	cause you grief during the initial boot! It is frequently not
273943d9616cSwdenk	used.
274043d9616cSwdenk
274143d9616cSwdenk	CFG_INIT_RAM_ADDR should be somewhere that won't interfere
274243d9616cSwdenk	with your processor/board/system design. The default value
274343d9616cSwdenk	you will find in any recent u-boot distribution in
274443d9616cSwdenk	Walnut405.h should work for you. I'd set it to a value larger
274543d9616cSwdenk	than your SDRAM module. If you have a 64MB SDRAM module, set
274643d9616cSwdenk	it above 400_0000. Just make sure your board has no resources
274743d9616cSwdenk	that are supposed to respond to that address! That code in
274843d9616cSwdenk	start.S has been around a while and should work as is when
274943d9616cSwdenk	you get the config right.
275043d9616cSwdenk
275143d9616cSwdenk	-Chris Hallinan
275243d9616cSwdenk	DS4.COM, Inc.
275343d9616cSwdenk
2754c609719bSwdenkIt is essential to remember this, since it has some impact on the C
2755c609719bSwdenkcode for the initialization procedures:
2756c609719bSwdenk
2757c609719bSwdenk* Initialized global data (data segment) is read-only. Do not attempt
2758c609719bSwdenk  to write it.
2759c609719bSwdenk
2760c609719bSwdenk* Do not use any unitialized global data (or implicitely initialized
2761c609719bSwdenk  as zero data - BSS segment) at all - this is undefined, initiali-
2762c609719bSwdenk  zation is performed later (when relocationg to RAM).
2763c609719bSwdenk
2764c609719bSwdenk* Stack space is very limited. Avoid big data buffers or things  like
2765c609719bSwdenk  that.
2766c609719bSwdenk
2767c609719bSwdenkHaving only the stack as writable memory limits means we cannot use
2768c609719bSwdenknormal global data to share information beween the code. But it
2769c609719bSwdenkturned out that the implementation of U-Boot can be greatly
2770c609719bSwdenksimplified by making a global data structure (gd_t) available to all
2771c609719bSwdenkfunctions. We could pass a pointer to this data as argument to _all_
2772c609719bSwdenkfunctions, but this would bloat the code. Instead we use a feature of
2773c609719bSwdenkthe GCC compiler (Global Register Variables) to share the data: we
2774c609719bSwdenkplace a pointer (gd) to the global data into a register which we
2775c609719bSwdenkreserve for this purpose.
2776c609719bSwdenk
2777c609719bSwdenkWhen chosing a register for such a purpose we are restricted  by  the
2778c609719bSwdenkrelevant  (E)ABI  specifications for the current architecture, and by
2779c609719bSwdenkGCC's implementation.
2780c609719bSwdenk
2781c609719bSwdenkFor PowerPC, the following registers have specific use:
2782c609719bSwdenk	R1:	stack pointer
2783c609719bSwdenk	R2:	TOC pointer
2784c609719bSwdenk	R3-R4:	parameter passing and return values
2785c609719bSwdenk	R5-R10:	parameter passing
2786c609719bSwdenk	R13:	small data area pointer
2787c609719bSwdenk	R30:	GOT pointer
2788c609719bSwdenk	R31:	frame pointer
2789c609719bSwdenk
2790c609719bSwdenk	(U-Boot also uses R14 as internal GOT pointer.)
2791c609719bSwdenk
2792c609719bSwdenk    ==> U-Boot will use R29 to hold a pointer to the global data
2793c609719bSwdenk
2794c609719bSwdenk    Note: on PPC, we could use a static initializer (since the
2795c609719bSwdenk    address of the global data structure is known at compile time),
2796c609719bSwdenk    but it turned out that reserving a register results in somewhat
2797c609719bSwdenk    smaller code - although the code savings are not that big (on
2798c609719bSwdenk    average for all boards 752 bytes for the whole U-Boot image,
2799c609719bSwdenk    624 text + 127 data).
2800c609719bSwdenk
2801c609719bSwdenkOn ARM, the following registers are used:
2802c609719bSwdenk
2803c609719bSwdenk	R0:	function argument word/integer result
2804c609719bSwdenk	R1-R3:	function argument word
2805c609719bSwdenk	R9:	GOT pointer
2806c609719bSwdenk	R10:	stack limit (used only if stack checking if enabled)
2807c609719bSwdenk	R11:	argument (frame) pointer
2808c609719bSwdenk	R12:	temporary workspace
2809c609719bSwdenk	R13:	stack pointer
2810c609719bSwdenk	R14:	link register
2811c609719bSwdenk	R15:	program counter
2812c609719bSwdenk
2813c609719bSwdenk    ==> U-Boot will use R8 to hold a pointer to the global data
2814c609719bSwdenk
2815c609719bSwdenk
2816c609719bSwdenk
2817c609719bSwdenkMemory Management:
2818c609719bSwdenk------------------
2819c609719bSwdenk
2820c609719bSwdenkU-Boot runs in system state and uses physical addresses, i.e. the
2821c609719bSwdenkMMU is not used either for address mapping nor for memory protection.
2822c609719bSwdenk
2823c609719bSwdenkThe available memory is mapped to fixed addresses using the memory
2824c609719bSwdenkcontroller. In this process, a contiguous block is formed for each
2825c609719bSwdenkmemory type (Flash, SDRAM, SRAM), even when it consists of several
2826c609719bSwdenkphysical memory banks.
2827c609719bSwdenk
2828c609719bSwdenkU-Boot is installed in the first 128 kB of the first Flash bank (on
2829c609719bSwdenkTQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2830c609719bSwdenkbooting and sizing and initializing DRAM, the code relocates itself
2831c609719bSwdenkto the upper end of DRAM. Immediately below the U-Boot code some
2832c609719bSwdenkmemory is reserved for use by malloc() [see CFG_MALLOC_LEN
2833c609719bSwdenkconfiguration setting]. Below that, a structure with global Board
2834c609719bSwdenkInfo data is placed, followed by the stack (growing downward).
2835c609719bSwdenk
2836c609719bSwdenkAdditionally, some exception handler code is copied to the low 8 kB
2837c609719bSwdenkof DRAM (0x00000000 ... 0x00001FFF).
2838c609719bSwdenk
2839c609719bSwdenkSo a typical memory configuration with 16 MB of DRAM could look like
2840c609719bSwdenkthis:
2841c609719bSwdenk
2842c609719bSwdenk	0x0000 0000	Exception Vector code
2843c609719bSwdenk	      :
2844c609719bSwdenk	0x0000 1FFF
2845c609719bSwdenk	0x0000 2000	Free for Application Use
2846c609719bSwdenk	      :
2847c609719bSwdenk	      :
2848c609719bSwdenk
2849c609719bSwdenk	      :
2850c609719bSwdenk	      :
2851c609719bSwdenk	0x00FB FF20	Monitor Stack (Growing downward)
2852c609719bSwdenk	0x00FB FFAC	Board Info Data and permanent copy of global data
2853c609719bSwdenk	0x00FC 0000	Malloc Arena
2854c609719bSwdenk	      :
2855c609719bSwdenk	0x00FD FFFF
2856c609719bSwdenk	0x00FE 0000	RAM Copy of Monitor Code
2857c609719bSwdenk	...		eventually: LCD or video framebuffer
2858c609719bSwdenk	...		eventually: pRAM (Protected RAM - unchanged by reset)
2859c609719bSwdenk	0x00FF FFFF	[End of RAM]
2860c609719bSwdenk
2861c609719bSwdenk
2862c609719bSwdenkSystem Initialization:
2863c609719bSwdenk----------------------
2864c609719bSwdenk
2865c609719bSwdenkIn the reset configuration, U-Boot starts at the reset entry point
2866c609719bSwdenk(on most PowerPC systens at address 0x00000100). Because of the reset
2867c609719bSwdenkconfiguration for CS0# this is a mirror of the onboard Flash memory.
2868c609719bSwdenkTo be able to re-map memory U-Boot then jumps to it's link address.
2869c609719bSwdenkTo be able to implement the initialization code in C, a (small!)
2870c609719bSwdenkinitial stack is set up in the internal Dual Ported RAM (in case CPUs
2871c609719bSwdenkwhich provide such a feature like MPC8xx or MPC8260), or in a locked
2872c609719bSwdenkpart of the data cache. After that, U-Boot initializes the CPU core,
2873c609719bSwdenkthe caches and the SIU.
2874c609719bSwdenk
2875c609719bSwdenkNext, all (potentially) available memory banks are mapped using a
2876c609719bSwdenkpreliminary mapping. For example, we put them on 512 MB boundaries
2877c609719bSwdenk(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2878c609719bSwdenkon 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2879c609719bSwdenkprogrammed for SDRAM access. Using the temporary configuration, a
2880c609719bSwdenksimple memory test is run that determines the size of the SDRAM
2881c609719bSwdenkbanks.
2882c609719bSwdenk
2883c609719bSwdenkWhen there is more than one SDRAM bank, and the banks are of
2884c609719bSwdenkdifferent size, the larger is mapped first. For equal size, the first
2885c609719bSwdenkbank (CS2#) is mapped first. The first mapping is always for address
2886c609719bSwdenk0x00000000, with any additional banks following immediately to create
2887c609719bSwdenkcontiguous memory starting from 0.
2888c609719bSwdenk
2889c609719bSwdenkThen, the monitor installs itself at the upper end of the SDRAM area
2890c609719bSwdenkand allocates memory for use by malloc() and for the global Board
2891c609719bSwdenkInfo data; also, the exception vector code is copied to the low RAM
2892c609719bSwdenkpages, and the final stack is set up.
2893c609719bSwdenk
2894c609719bSwdenkOnly after this relocation will you have a "normal" C environment;
2895c609719bSwdenkuntil that you are restricted in several ways, mostly because you are
2896c609719bSwdenkrunning from ROM, and because the code will have to be relocated to a
2897c609719bSwdenknew address in RAM.
2898c609719bSwdenk
2899c609719bSwdenk
2900c609719bSwdenkU-Boot Porting Guide:
2901c609719bSwdenk----------------------
2902c609719bSwdenk
2903c609719bSwdenk[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
29046aff3115Swdenklist, October 2002]
2905c609719bSwdenk
2906c609719bSwdenk
2907c609719bSwdenkint main (int argc, char *argv[])
2908c609719bSwdenk{
2909c609719bSwdenk	sighandler_t no_more_time;
2910c609719bSwdenk
2911c609719bSwdenk	signal (SIGALRM, no_more_time);
2912c609719bSwdenk	alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2913c609719bSwdenk
2914c609719bSwdenk	if (available_money > available_manpower) {
2915c609719bSwdenk		pay consultant to port U-Boot;
2916c609719bSwdenk		return 0;
2917c609719bSwdenk	}
2918c609719bSwdenk
2919c609719bSwdenk	Download latest U-Boot source;
2920c609719bSwdenk
29216aff3115Swdenk	Subscribe to u-boot-users mailing list;
29226aff3115Swdenk
2923c609719bSwdenk	if (clueless) {
2924c609719bSwdenk		email ("Hi, I am new to U-Boot, how do I get started?");
2925c609719bSwdenk	}
2926c609719bSwdenk
2927c609719bSwdenk	while (learning) {
2928c609719bSwdenk		Read the README file in the top level directory;
2929c609719bSwdenk		Read http://www.denx.de/re/DPLG.html
2930c609719bSwdenk		Read the source, Luke;
2931c609719bSwdenk	}
2932c609719bSwdenk
2933c609719bSwdenk	if (available_money > toLocalCurrency ($2500)) {
2934c609719bSwdenk		Buy a BDI2000;
2935c609719bSwdenk	} else {
2936c609719bSwdenk		Add a lot of aggravation and time;
2937c609719bSwdenk	}
2938c609719bSwdenk
2939c609719bSwdenk	Create your own board support subdirectory;
2940c609719bSwdenk
29416aff3115Swdenk	Create your own board config file;
29426aff3115Swdenk
2943c609719bSwdenk	while (!running) {
2944c609719bSwdenk		do {
2945c609719bSwdenk			Add / modify source code;
2946c609719bSwdenk		} until (compiles);
2947c609719bSwdenk		Debug;
2948c609719bSwdenk		if (clueless)
2949c609719bSwdenk			email ("Hi, I am having problems...");
2950c609719bSwdenk	}
2951c609719bSwdenk	Send patch file to Wolfgang;
2952c609719bSwdenk
2953c609719bSwdenk	return 0;
2954c609719bSwdenk}
2955c609719bSwdenk
2956c609719bSwdenkvoid no_more_time (int sig)
2957c609719bSwdenk{
2958c609719bSwdenk      hire_a_guru();
2959c609719bSwdenk}
2960c609719bSwdenk
2961c609719bSwdenk
2962c609719bSwdenk
2963c609719bSwdenkCoding Standards:
2964c609719bSwdenk-----------------
2965c609719bSwdenk
2966c609719bSwdenkAll contributions to U-Boot should conform to the Linux kernel
2967c609719bSwdenkcoding style; see the file "Documentation/CodingStyle" in your Linux
2968c609719bSwdenkkernel source directory.
2969c609719bSwdenk
2970c609719bSwdenkPlease note that U-Boot is implemented in C (and to some small parts
2971c609719bSwdenkin Assembler); no C++ is used, so please do not use C++ style
2972c609719bSwdenkcomments (//) in your code.
2973c609719bSwdenk
2974c609719bSwdenkSubmissions which do not conform to the standards may be returned
2975c609719bSwdenkwith a request to reformat the changes.
2976c609719bSwdenk
2977c609719bSwdenk
2978c609719bSwdenkSubmitting Patches:
2979c609719bSwdenk-------------------
2980c609719bSwdenk
2981c609719bSwdenkSince the number of patches for U-Boot is growing, we need to
2982c609719bSwdenkestablish some rules. Submissions which do not conform to these rules
2983c609719bSwdenkmay be rejected, even when they contain important and valuable stuff.
2984c609719bSwdenk
2985c609719bSwdenk
2986c609719bSwdenkWhen you send a patch, please include the following information with
2987c609719bSwdenkit:
2988c609719bSwdenk
2989c609719bSwdenk* For bug fixes: a description of the bug and how your patch fixes
2990c609719bSwdenk  this bug. Please try to include a way of demonstrating that the
2991c609719bSwdenk  patch actually fixes something.
2992c609719bSwdenk
2993c609719bSwdenk* For new features: a description of the feature and your
2994c609719bSwdenk  implementation.
2995c609719bSwdenk
2996c609719bSwdenk* A CHANGELOG entry as plaintext (separate from the patch)
2997c609719bSwdenk
2998c609719bSwdenk* For major contributions, your entry to the CREDITS file
2999c609719bSwdenk
3000c609719bSwdenk* When you add support for a new board, don't forget to add this
3001c609719bSwdenk  board to the MAKEALL script, too.
3002c609719bSwdenk
3003c609719bSwdenk* If your patch adds new configuration options, don't forget to
3004c609719bSwdenk  document these in the README file.
3005c609719bSwdenk
3006c609719bSwdenk* The patch itself. If you are accessing the CVS repository use "cvs
3007c609719bSwdenk  update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
3008c609719bSwdenk  version of diff does not support these options, then get the latest
3009c609719bSwdenk  version of GNU diff.
3010c609719bSwdenk
3011c609719bSwdenk  We accept patches as plain text, MIME attachments or as uuencoded
3012c609719bSwdenk  gzipped text.
3013c609719bSwdenk
301452f52c14Swdenk* If one logical set of modifications affects or creates several
301552f52c14Swdenk  files, all these changes shall be submitted in a SINGLE patch file.
301652f52c14Swdenk
301752f52c14Swdenk* Changesets that contain different, unrelated modifications shall be
301852f52c14Swdenk  submitted as SEPARATE patches, one patch per changeset.
301952f52c14Swdenk
302052f52c14Swdenk
3021c609719bSwdenkNotes:
3022c609719bSwdenk
3023c609719bSwdenk* Before sending the patch, run the MAKEALL script on your patched
3024c609719bSwdenk  source tree and make sure that no errors or warnings are reported
3025c609719bSwdenk  for any of the boards.
3026c609719bSwdenk
3027c609719bSwdenk* Keep your modifications to the necessary minimum: A patch
3028c609719bSwdenk  containing several unrelated changes or arbitrary reformats will be
3029c609719bSwdenk  returned with a request to re-formatting / split it.
3030c609719bSwdenk
3031c609719bSwdenk* If you modify existing code, make sure that your new code does not
3032c609719bSwdenk  add to the memory footprint of the code ;-) Small is beautiful!
3033c609719bSwdenk  When adding new features, these should compile conditionally only
3034c609719bSwdenk  (using #ifdef), and the resulting code with the new feature
3035c609719bSwdenk  disabled must not need more memory than the old code without your
3036c609719bSwdenk  modification.
3037