xref: /openbmc/u-boot/README (revision 43d9616cffb4a130e1620e3e33fc9bc1bcabe399)
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
143c609719bSwdenk- cpu/mpc8xx	Files specific to Motorola MPC8xx  CPUs
144c609719bSwdenk- cpu/mpc824x	Files specific to Motorola MPC824x CPUs
145c609719bSwdenk- cpu/mpc8260	Files specific to Motorola MPC8260 CPU
146c609719bSwdenk- cpu/ppc4xx	Files specific to IBM	   4xx	   CPUs
147c609719bSwdenk
148c609719bSwdenk- board/RPXClassic
149c609719bSwdenk		Files specific to RPXClassic boards
150c609719bSwdenk- board/RPXlite	Files specific to RPXlite    boards
151c609719bSwdenk- board/c2mon	Files specific to c2mon	     boards
152c609719bSwdenk- board/cogent	Files specific to Cogent     boards
153c609719bSwdenk		(need further configuration)
154c609719bSwdenk		Files specific to CPCIISER4  boards
155c609719bSwdenk- board/cpu86	Files specific to CPU86      boards
156c609719bSwdenk- board/cray/	Files specific to boards manufactured by Cray
157c609719bSwdenk- board/cray/L1		Files specific to L1         boards
158c609719bSwdenk- board/cu824	Files specific to CU824	     boards
159c609719bSwdenk- board/ebony   Files specific to IBM Ebony board
160c609719bSwdenk- board/eric	Files specific to ERIC	     boards
161c609719bSwdenk- board/esd/	Files specific to boards manufactured by ESD
162c609719bSwdenk- board/esd/adciop	Files specific to ADCIOP     boards
163c609719bSwdenk- board/esd/ar405	Files specific to AR405	     boards
164c609719bSwdenk- board/esd/canbt	Files specific to CANBT	     boards
165c609719bSwdenk- board/esd/cpci405	Files specific to CPCI405    boards
166c609719bSwdenk- board/esd/cpciiser4	Files specific to CPCIISER4  boards
167c609719bSwdenk- board/esd/common	Common files for ESD boards
168c609719bSwdenk- board/esd/dasa_sim	Files specific to DASA_SIM   boards
169c609719bSwdenk- board/esd/du405	Files specific to DU405      boards
170c609719bSwdenk- board/esd/ocrtc	Files specific to OCRTC      boards
171c609719bSwdenk- board/esd/pci405	Files specific to PCI405     boards
172c609719bSwdenk- board/esteem192e
173c609719bSwdenk		Files specific to ESTEEM192E boards
174c609719bSwdenk- board/etx094	Files specific to ETX_094    boards
175c609719bSwdenk- board/evb64260
176c609719bSwdenk		Files specific to EVB64260   boards
177c609719bSwdenk- board/fads	Files specific to FADS	     boards
178c609719bSwdenk- board/flagadm Files specific to FLAGADM    boards
179c609719bSwdenk- board/gen860t Files specific to GEN860T    boards
180c609719bSwdenk- board/genietv Files specific to GENIETV    boards
181c609719bSwdenk- board/gth	Files specific to GTH	     boards
182c609719bSwdenk- board/hermes	Files specific to HERMES     boards
183c609719bSwdenk- board/hymod	Files specific to HYMOD	     boards
184c609719bSwdenk- board/icu862	Files specific to ICU862     boards
185c609719bSwdenk- board/ip860	Files specific to IP860	     boards
186c609719bSwdenk- board/iphase4539
187c609719bSwdenk		Files specific to Interphase4539 boards
188c609719bSwdenk- board/ivm	Files specific to IVMS8/IVML24 boards
189c609719bSwdenk- board/lantec	Files specific to LANTEC     boards
190c609719bSwdenk- board/lwmon	Files specific to LWMON	     boards
191c609719bSwdenk- board/mbx8xx	Files specific to MBX	     boards
192c609719bSwdenk- board/mpc8260ads
193c609719bSwdenk		Files specific to MMPC8260ADS boards
194c609719bSwdenk- board/mpl/	Files specific to boards manufactured by MPL
195c609719bSwdenk- board/mpl/common	Common files for MPL boards
196c609719bSwdenk- board/mpl/pip405	Files specific to PIP405     boards
197c609719bSwdenk- board/mpl/mip405	Files specific to MIP405     boards
198c609719bSwdenk- board/musenki	Files specific to MUSEKNI    boards
199c609719bSwdenk- board/mvs1	Files specific to MVS1       boards
200c609719bSwdenk- board/nx823   Files specific to NX823      boards
201c609719bSwdenk- board/oxc	Files specific to OXC        boards
202c609719bSwdenk- board/pcippc2	Files specific to PCIPPC2/PCIPPC6 boards
203c609719bSwdenk- board/pm826	Files specific to PM826      boards
204c609719bSwdenk- board/ppmc8260
205c609719bSwdenk		Files specific to PPMC8260   boards
206c609719bSwdenk- board/rpxsuper
207c609719bSwdenk		Files specific to RPXsuper   boards
208c609719bSwdenk- board/rsdproto
209c609719bSwdenk		Files specific to RSDproto   boards
210c609719bSwdenk- board/sandpoint
211c609719bSwdenk		Files specific to Sandpoint  boards
212c609719bSwdenk- board/sbc8260	Files specific to SBC8260    boards
213c609719bSwdenk- board/sacsng	Files specific to SACSng     boards
214c609719bSwdenk- board/siemens Files specific to boards manufactured by Siemens AG
215c609719bSwdenk- board/siemens/CCM	Files specific to CCM	     boards
216c609719bSwdenk- board/siemens/IAD210	Files specific to IAD210     boards
217c609719bSwdenk- board/siemens/SCM	Files specific to SCM        boards
218c609719bSwdenk- board/siemens/pcu_e	Files specific to PCU_E	     boards
219c609719bSwdenk- board/sixnet	Files specific to SIXNET     boards
220c609719bSwdenk- board/spd8xx	Files specific to SPD8xxTS   boards
221c609719bSwdenk- board/tqm8260 Files specific to TQM8260    boards
222c609719bSwdenk- board/tqm8xx	Files specific to TQM8xxL    boards
223c609719bSwdenk- board/w7o	Files specific to W7O        boards
224c609719bSwdenk- board/walnut405
225c609719bSwdenk		Files specific to Walnut405  boards
226c609719bSwdenk- board/westel/	Files specific to boards manufactured by Westel Wireless
227c609719bSwdenk- board/westel/amx860	Files specific to AMX860     boards
228c609719bSwdenk- board/utx8245	Files specific to UTX8245   boards
229c609719bSwdenk
230c609719bSwdenkSoftware Configuration:
231c609719bSwdenk=======================
232c609719bSwdenk
233c609719bSwdenkConfiguration is usually done using C preprocessor defines; the
234c609719bSwdenkrationale behind that is to avoid dead code whenever possible.
235c609719bSwdenk
236c609719bSwdenkThere are two classes of configuration variables:
237c609719bSwdenk
238c609719bSwdenk* Configuration _OPTIONS_:
239c609719bSwdenk  These are selectable by the user and have names beginning with
240c609719bSwdenk  "CONFIG_".
241c609719bSwdenk
242c609719bSwdenk* Configuration _SETTINGS_:
243c609719bSwdenk  These depend on the hardware etc. and should not be meddled with if
244c609719bSwdenk  you don't know what you're doing; they have names beginning with
245c609719bSwdenk  "CFG_".
246c609719bSwdenk
247c609719bSwdenkLater we will add a configuration tool - probably similar to or even
248c609719bSwdenkidentical to what's used for the Linux kernel. Right now, we have to
249c609719bSwdenkdo the configuration by hand, which means creating some symbolic
250c609719bSwdenklinks and editing some configuration files. We use the TQM8xxL boards
251c609719bSwdenkas an example here.
252c609719bSwdenk
253c609719bSwdenk
254c609719bSwdenkSelection of Processor Architecture and Board Type:
255c609719bSwdenk---------------------------------------------------
256c609719bSwdenk
257c609719bSwdenkFor all supported boards there are ready-to-use default
258c609719bSwdenkconfigurations available; just type "make <board_name>_config".
259c609719bSwdenk
260c609719bSwdenkExample: For a TQM823L module type:
261c609719bSwdenk
262c609719bSwdenk	cd u-boot
263c609719bSwdenk	make TQM823L_config
264c609719bSwdenk
265c609719bSwdenkFor the Cogent platform, you need to specify the cpu type as well;
266c609719bSwdenke.g. "make cogent_mpc8xx_config". And also configure the cogent
267c609719bSwdenkdirectory according to the instructions in cogent/README.
268c609719bSwdenk
269c609719bSwdenk
270c609719bSwdenkConfiguration Options:
271c609719bSwdenk----------------------
272c609719bSwdenk
273c609719bSwdenkConfiguration depends on the combination of board and CPU type; all
274c609719bSwdenksuch information is kept in a configuration file
275c609719bSwdenk"include/configs/<board_name>.h".
276c609719bSwdenk
277c609719bSwdenkExample: For a TQM823L module, all configuration settings are in
278c609719bSwdenk"include/configs/TQM823L.h".
279c609719bSwdenk
280c609719bSwdenk
2817f6c2cbcSwdenkMany of the options are named exactly as the corresponding Linux
2827f6c2cbcSwdenkkernel configuration options. The intention is to make it easier to
2837f6c2cbcSwdenkbuild a config tool - later.
2847f6c2cbcSwdenk
2857f6c2cbcSwdenk
286c609719bSwdenkThe following options need to be configured:
287c609719bSwdenk
288c609719bSwdenk- CPU Type:	Define exactly one of
289c609719bSwdenk
290c609719bSwdenk		PowerPC based CPUs:
291c609719bSwdenk		-------------------
292c609719bSwdenk		CONFIG_MPC823,	CONFIG_MPC850,	CONFIG_MPC855,	CONFIG_MPC860
293c609719bSwdenk	or	CONFIG_MPC824X, CONFIG_MPC8260
294c609719bSwdenk	or	CONFIG_IOP480
295c609719bSwdenk	or	CONFIG_405GP
296c609719bSwdenk	or	CONFIG_440
297c609719bSwdenk	or	CONFIG_MPC74xx
298c609719bSwdenk
299c609719bSwdenk		ARM based CPUs:
300c609719bSwdenk		---------------
301c609719bSwdenk		CONFIG_SA1110
302c609719bSwdenk		CONFIG_ARM7
303c609719bSwdenk		CONFIG_PXA250
304c609719bSwdenk
305c609719bSwdenk
306c609719bSwdenk- Board Type:	Define exactly one of
307c609719bSwdenk
308c609719bSwdenk		PowerPC based boards:
309c609719bSwdenk		---------------------
310c609719bSwdenk
311c609719bSwdenk		CONFIG_ADCIOP,     CONFIG_ICU862      CONFIG_RPXsuper,
312c609719bSwdenk		CONFIG_ADS860,     CONFIG_IP860,      CONFIG_SM850,
313c609719bSwdenk		CONFIG_AMX860,     CONFIG_IPHASE4539, CONFIG_SPD823TS,
314c609719bSwdenk		CONFIG_AR405,      CONFIG_IVML24,     CONFIG_SXNI855T,
315c609719bSwdenk		CONFIG_BAB7xx,     CONFIG_IVML24_128, CONFIG_Sandpoint8240,
316c609719bSwdenk		CONFIG_CANBT,      CONFIG_IVML24_256, CONFIG_Sandpoint8245,
317c609719bSwdenk		CONFIG_CCM,        CONFIG_IVMS8,      CONFIG_TQM823L,
318c609719bSwdenk		CONFIG_CPCI405,    CONFIG_IVMS8_128,  CONFIG_TQM850L,
319c609719bSwdenk		CONFIG_CPCI4052,   CONFIG_IVMS8_256,  CONFIG_TQM855L,
320c609719bSwdenk		CONFIG_CPCIISER4,  CONFIG_LANTEC,     CONFIG_TQM860L,
321c609719bSwdenk		CONFIG_CPU86,      CONFIG_MBX,        CONFIG_TQM8260,
322c609719bSwdenk		CONFIG_CRAYL1,     CONFIG_MBX860T,    CONFIG_TTTech,
323c609719bSwdenk		CONFIG_CU824,      CONFIG_MHPC,       CONFIG_UTX8245,
324c609719bSwdenk		CONFIG_DASA_SIM,   CONFIG_MIP405,     CONFIG_W7OLMC,
325c609719bSwdenk		CONFIG_DU405,      CONFIG_MOUSSE,     CONFIG_W7OLMG,
326c609719bSwdenk		CONFIG_ELPPC,      CONFIG_MPC8260ADS, CONFIG_WALNUT405,
327c609719bSwdenk		CONFIG_ERIC,       CONFIG_MUSENKI,    CONFIG_ZUMA,
328c609719bSwdenk		CONFIG_ESTEEM192E, CONFIG_MVS1,       CONFIG_c2mon,
329c609719bSwdenk		CONFIG_ETX094,     CONFIG_NX823,      CONFIG_cogent_mpc8260,
330c609719bSwdenk		CONFIG_EVB64260,   CONFIG_OCRTC,      CONFIG_cogent_mpc8xx,
331c609719bSwdenk		CONFIG_FADS823,    CONFIG_ORSG,       CONFIG_ep8260,
332c609719bSwdenk		CONFIG_FADS850SAR, CONFIG_OXC,        CONFIG_gw8260,
333c609719bSwdenk		CONFIG_FADS860T,   CONFIG_PCI405,     CONFIG_hermes,
334c609719bSwdenk		CONFIG_FLAGADM,    CONFIG_PCIPPC2,    CONFIG_hymod,
335c609719bSwdenk		CONFIG_FPS850L,    CONFIG_PCIPPC6,    CONFIG_lwmon,
336c609719bSwdenk		CONFIG_GEN860T,    CONFIG_PIP405,     CONFIG_pcu_e,
337c609719bSwdenk		CONFIG_GENIETV,    CONFIG_PM826,      CONFIG_ppmc8260,
338c609719bSwdenk		CONFIG_GTH,        CONFIG_RPXClassic, CONFIG_rsdproto,
339c609719bSwdenk		CONFIG_IAD210,     CONFIG_RPXlite,    CONFIG_sbc8260,
340608c9146Swdenk		CONFIG_EBONY,      CONFIG_sacsng,     CONFIG_FPS860L,
341608c9146Swdenk		CONFIG_V37
342c609719bSwdenk
343c609719bSwdenk		ARM based boards:
344c609719bSwdenk		-----------------
345c609719bSwdenk
346c609719bSwdenk		CONFIG_HHP_CRADLE,  CONFIG_DNP1110,    CONFIG_EP7312,
347c609719bSwdenk		CONFIG_IMPA7,       CONFIG_LART,       CONFIG_LUBBOCK,
348c609719bSwdenk		CONFIG_SHANNON,     CONFIG_SMDK2400,   CONFIG_SMDK2410,
349c609719bSwdenk		CONFIG_TRAB
350c609719bSwdenk
351c609719bSwdenk
352c609719bSwdenk- CPU Module Type: (if CONFIG_COGENT is defined)
353c609719bSwdenk		Define exactly one of
354c609719bSwdenk		CONFIG_CMA286_60_OLD
355c609719bSwdenk--- FIXME --- not tested yet:
356c609719bSwdenk		CONFIG_CMA286_60, CONFIG_CMA286_21, CONFIG_CMA286_60P,
357c609719bSwdenk		CONFIG_CMA287_23, CONFIG_CMA287_50
358c609719bSwdenk
359c609719bSwdenk- Motherboard Type: (if CONFIG_COGENT is defined)
360c609719bSwdenk		Define exactly one of
361c609719bSwdenk		CONFIG_CMA101, CONFIG_CMA102
362c609719bSwdenk
363c609719bSwdenk- Motherboard I/O Modules: (if CONFIG_COGENT is defined)
364c609719bSwdenk		Define one or more of
365c609719bSwdenk		CONFIG_CMA302
366c609719bSwdenk
367c609719bSwdenk- Motherboard Options: (if CONFIG_CMA101 or CONFIG_CMA102 are defined)
368c609719bSwdenk		Define one or more of
369c609719bSwdenk		CONFIG_LCD_HEARTBEAT	- update a character position on
370c609719bSwdenk					  the lcd display every second with
371c609719bSwdenk					  a "rotator" |\-/|\-/
372c609719bSwdenk
373c609719bSwdenk- MPC824X Family Member (if CONFIG_MPC824X is defined)
374c609719bSwdenk	Define exactly one of
375c609719bSwdenk	CONFIG_MPC8240, CONFIG_MPC8245
376c609719bSwdenk
377c609719bSwdenk- 8xx CPU Options: (if using an 8xx cpu)
378c609719bSwdenk		Define one or more of
379c609719bSwdenk		CONFIG_8xx_GCLK_FREQ	- if get_gclk_freq() can not work e.g.
380c609719bSwdenk					  no 32KHz reference PIT/RTC clock
381c609719bSwdenk
382c609719bSwdenk- Clock Interface:
383c609719bSwdenk		CONFIG_CLOCKS_IN_MHZ
384c609719bSwdenk
385c609719bSwdenk		U-Boot stores all clock information in Hz
386c609719bSwdenk		internally. For binary compatibility with older Linux
387c609719bSwdenk		kernels (which expect the clocks passed in the
388c609719bSwdenk		bd_info data to be in MHz) the environment variable
389c609719bSwdenk		"clocks_in_mhz" can be defined so that U-Boot
390c609719bSwdenk		converts clock data to MHZ before passing it to the
391c609719bSwdenk		Linux kernel.
392c609719bSwdenk
393c609719bSwdenk		When CONFIG_CLOCKS_IN_MHZ is defined, a definition of
394c609719bSwdenk		"clocks_in_mhz=1" is  automatically  included  in  the
395c609719bSwdenk		default environment.
396c609719bSwdenk
397c609719bSwdenk- Console Interface:
398c609719bSwdenk		Depending on board, define exactly one serial port
399c609719bSwdenk		(like CONFIG_8xx_CONS_SMC1, CONFIG_8xx_CONS_SMC2,
400c609719bSwdenk		CONFIG_8xx_CONS_SCC1, ...), or switch off the serial
401c609719bSwdenk		console by defining CONFIG_8xx_CONS_NONE
402c609719bSwdenk
403c609719bSwdenk		Note: if CONFIG_8xx_CONS_NONE is defined, the serial
404c609719bSwdenk		port routines must be defined elsewhere
405c609719bSwdenk		(i.e. serial_init(), serial_getc(), ...)
406c609719bSwdenk
407c609719bSwdenk		CONFIG_CFB_CONSOLE
408c609719bSwdenk		Enables console device for a color framebuffer. Needs following
409c609719bSwdenk		defines (cf. smiLynxEM, i8042, board/eltec/bab7xx)
410c609719bSwdenk			VIDEO_FB_LITTLE_ENDIAN	graphic memory organisation
411c609719bSwdenk						(default big endian)
412c609719bSwdenk			VIDEO_HW_RECTFILL	graphic chip supports
413c609719bSwdenk						rectangle fill
414c609719bSwdenk						(cf. smiLynxEM)
415c609719bSwdenk			VIDEO_HW_BITBLT		graphic chip supports
416c609719bSwdenk						bit-blit (cf. smiLynxEM)
417c609719bSwdenk			VIDEO_VISIBLE_COLS	visible pixel columns
418c609719bSwdenk						(cols=pitch)
419c609719bSwdenk			VIDEO_VISIBLE_ROWS      visible pixel rows
420c609719bSwdenk			VIDEO_PIXEL_SIZE        bytes per pixel
421c609719bSwdenk			VIDEO_DATA_FORMAT	graphic data format
422c609719bSwdenk						(0-5, cf. cfb_console.c)
423c609719bSwdenk			VIDEO_FB_ADRS           framebuffer address
424c609719bSwdenk			VIDEO_KBD_INIT_FCT	keyboard int fct
425c609719bSwdenk						(i.e. i8042_kbd_init())
426c609719bSwdenk			VIDEO_TSTC_FCT		test char fct
427c609719bSwdenk						(i.e. i8042_tstc)
428c609719bSwdenk			VIDEO_GETC_FCT		get char fct
429c609719bSwdenk						(i.e. i8042_getc)
430c609719bSwdenk			CONFIG_CONSOLE_CURSOR	cursor drawing on/off
431c609719bSwdenk						(requires blink timer
432c609719bSwdenk						cf. i8042.c)
433c609719bSwdenk			CFG_CONSOLE_BLINK_COUNT blink interval (cf. i8042.c)
434c609719bSwdenk			CONFIG_CONSOLE_TIME	display time/date info in
435c609719bSwdenk						upper right corner
436c609719bSwdenk						(requires CFG_CMD_DATE)
437c609719bSwdenk			CONFIG_VIDEO_LOGO	display Linux logo in
438c609719bSwdenk						upper left corner
439a6c7ad2fSwdenk			CONFIG_VIDEO_BMP_LOGO	use bmp_logo.h instead of
440a6c7ad2fSwdenk						linux_logo.h for logo.
441a6c7ad2fSwdenk						Requires CONFIG_VIDEO_LOGO
442c609719bSwdenk			CONFIG_CONSOLE_EXTRA_INFO
443c609719bSwdenk						addional board info beside
444c609719bSwdenk						the logo
445c609719bSwdenk
446c609719bSwdenk		When CONFIG_CFB_CONSOLE is defined, video console is
447c609719bSwdenk		default i/o. Serial console can be forced with
448c609719bSwdenk		environment 'console=serial'.
449c609719bSwdenk
450c609719bSwdenk- Console Baudrate:
451c609719bSwdenk		CONFIG_BAUDRATE - in bps
452c609719bSwdenk		Select one of the baudrates listed in
453c609719bSwdenk		CFG_BAUDRATE_TABLE, see below.
454c609719bSwdenk
455c609719bSwdenk- Interrupt driven serial port input:
456c609719bSwdenk		CONFIG_SERIAL_SOFTWARE_FIFO
457c609719bSwdenk
458c609719bSwdenk		PPC405GP only.
459c609719bSwdenk		Use an interrupt handler for receiving data on the
460c609719bSwdenk		serial port. It also enables using hardware handshake
461c609719bSwdenk		(RTS/CTS) and UART's built-in FIFO. Set the number of
462c609719bSwdenk		bytes the interrupt driven input buffer should have.
463c609719bSwdenk
464c609719bSwdenk		Set to 0 to disable this feature (this is the default).
465c609719bSwdenk		This will also disable hardware handshake.
466c609719bSwdenk
467c609719bSwdenk- Boot Delay:	CONFIG_BOOTDELAY - in seconds
468c609719bSwdenk		Delay before automatically booting the default image;
469c609719bSwdenk		set to -1 to disable autoboot.
470c609719bSwdenk
471c609719bSwdenk		See doc/README.autoboot for these options that
472c609719bSwdenk		work with CONFIG_BOOTDELAY. None are required.
473c609719bSwdenk		CONFIG_BOOT_RETRY_TIME
474c609719bSwdenk		CONFIG_BOOT_RETRY_MIN
475c609719bSwdenk		CONFIG_AUTOBOOT_KEYED
476c609719bSwdenk		CONFIG_AUTOBOOT_PROMPT
477c609719bSwdenk		CONFIG_AUTOBOOT_DELAY_STR
478c609719bSwdenk		CONFIG_AUTOBOOT_STOP_STR
479c609719bSwdenk		CONFIG_AUTOBOOT_DELAY_STR2
480c609719bSwdenk		CONFIG_AUTOBOOT_STOP_STR2
481c609719bSwdenk		CONFIG_ZERO_BOOTDELAY_CHECK
482c609719bSwdenk		CONFIG_RESET_TO_RETRY
483c609719bSwdenk
484c609719bSwdenk- Autoboot Command:
485c609719bSwdenk		CONFIG_BOOTCOMMAND
486c609719bSwdenk		Only needed when CONFIG_BOOTDELAY is enabled;
487c609719bSwdenk		define a command string that is automatically executed
488c609719bSwdenk		when no character is read on the console interface
489c609719bSwdenk		within "Boot Delay" after reset.
490c609719bSwdenk
491c609719bSwdenk		CONFIG_BOOTARGS
492c609719bSwdenk		This can be used to pass arguments to the bootm
493c609719bSwdenk		command. The value of CONFIG_BOOTARGS goes into the
494c609719bSwdenk		environment value "bootargs".
495c609719bSwdenk
496c609719bSwdenk		CONFIG_RAMBOOT and CONFIG_NFSBOOT
497c609719bSwdenk		The value of these goes into the environment as
498c609719bSwdenk		"ramboot" and "nfsboot" respectively, and can be used
499c609719bSwdenk		as a convenience, when switching between booting from
500c609719bSwdenk		ram and nfs.
501c609719bSwdenk
502c609719bSwdenk- Pre-Boot Commands:
503c609719bSwdenk		CONFIG_PREBOOT
504c609719bSwdenk
505c609719bSwdenk		When this option is #defined, the existence of the
506c609719bSwdenk		environment variable "preboot" will be checked
507c609719bSwdenk		immediately before starting the CONFIG_BOOTDELAY
508c609719bSwdenk		countdown and/or running the auto-boot command resp.
509c609719bSwdenk		entering interactive mode.
510c609719bSwdenk
511c609719bSwdenk		This feature is especially useful when "preboot" is
512c609719bSwdenk		automatically generated or modified. For an example
513c609719bSwdenk		see the LWMON board specific code: here "preboot" is
514c609719bSwdenk		modified when the user holds down a certain
515c609719bSwdenk		combination of keys on the (special) keyboard when
516c609719bSwdenk		booting the systems
517c609719bSwdenk
518c609719bSwdenk- Serial Download Echo Mode:
519c609719bSwdenk		CONFIG_LOADS_ECHO
520c609719bSwdenk		If defined to 1, all characters received during a
521c609719bSwdenk		serial download (using the "loads" command) are
522c609719bSwdenk		echoed back. This might be needed by some terminal
523c609719bSwdenk		emulations (like "cu"), but may as well just take
524c609719bSwdenk		time on others. This setting #define's the initial
525c609719bSwdenk		value of the "loads_echo" environment variable.
526c609719bSwdenk
527c609719bSwdenk- Kgdb Serial Baudrate: (if CFG_CMD_KGDB is defined)
528c609719bSwdenk		CONFIG_KGDB_BAUDRATE
529c609719bSwdenk		Select one of the baudrates listed in
530c609719bSwdenk		CFG_BAUDRATE_TABLE, see below.
531c609719bSwdenk
532c609719bSwdenk- Monitor Functions:
533c609719bSwdenk		CONFIG_COMMANDS
534c609719bSwdenk		Most monitor functions can be selected (or
535c609719bSwdenk		de-selected) by adjusting the definition of
536c609719bSwdenk		CONFIG_COMMANDS; to select individual functions,
537c609719bSwdenk		#define CONFIG_COMMANDS by "OR"ing any of the
538c609719bSwdenk		following values:
539c609719bSwdenk
540c609719bSwdenk		#define enables commands:
541c609719bSwdenk		-------------------------
542c609719bSwdenk		CFG_CMD_ASKENV	* ask for env variable
543c609719bSwdenk		CFG_CMD_BDI	  bdinfo
544c609719bSwdenk		CFG_CMD_BEDBUG	  Include BedBug Debugger
545c609719bSwdenk		CFG_CMD_BOOTD	  bootd
546c609719bSwdenk		CFG_CMD_CACHE	  icache, dcache
547c609719bSwdenk		CFG_CMD_CONSOLE	  coninfo
548c609719bSwdenk		CFG_CMD_DATE	* support for RTC, date/time...
549c609719bSwdenk		CFG_CMD_DHCP	  DHCP support
550c609719bSwdenk		CFG_CMD_ECHO	* echo arguments
551c609719bSwdenk		CFG_CMD_EEPROM	* EEPROM read/write support
552c609719bSwdenk		CFG_CMD_ELF	  bootelf, bootvx
553c609719bSwdenk		CFG_CMD_ENV	  saveenv
554c609719bSwdenk		CFG_CMD_FDC	* Floppy Disk Support
5552262cfeeSwdenk		CFG_CMD_FDOS	* Dos diskette Support
556c609719bSwdenk		CFG_CMD_FLASH	  flinfo, erase, protect
557c609719bSwdenk		CFG_CMD_FPGA	  FPGA device initialization support
558c609719bSwdenk		CFG_CMD_I2C	* I2C serial bus support
559c609719bSwdenk		CFG_CMD_IDE	* IDE harddisk support
560c609719bSwdenk		CFG_CMD_IMI	  iminfo
561c609719bSwdenk		CFG_CMD_IMMAP	* IMMR dump support
562c609719bSwdenk		CFG_CMD_IRQ	* irqinfo
563c609719bSwdenk		CFG_CMD_KGDB	* kgdb
564c609719bSwdenk		CFG_CMD_LOADB	  loadb
565c609719bSwdenk		CFG_CMD_LOADS	  loads
566c609719bSwdenk		CFG_CMD_MEMORY	  md, mm, nm, mw, cp, cmp, crc, base,
567c609719bSwdenk				  loop, mtest
568c609719bSwdenk		CFG_CMD_MII	  MII utility commands
569c609719bSwdenk		CFG_CMD_NET	  bootp, tftpboot, rarpboot
570c609719bSwdenk		CFG_CMD_PCI	* pciinfo
571c609719bSwdenk		CFG_CMD_PCMCIA	* PCMCIA support
572c609719bSwdenk		CFG_CMD_REGINFO * Register dump
573c609719bSwdenk		CFG_CMD_RUN	  run command in env variable
574c609719bSwdenk		CFG_CMD_SCSI	* SCSI Support
575c609719bSwdenk		CFG_CMD_SETGETDCR Support for DCR Register access (4xx only)
576c609719bSwdenk		CFG_CMD_SPI	* SPI serial bus support
577c609719bSwdenk		CFG_CMD_USB	* USB support
578c609719bSwdenk		CFG_CMD_BSP	* Board SPecific functions
579c609719bSwdenk		-----------------------------------------------
580c609719bSwdenk		CFG_CMD_ALL	all
581c609719bSwdenk
582c609719bSwdenk		CFG_CMD_DFL	Default configuration; at the moment
583c609719bSwdenk				this is includes all commands, except
584c609719bSwdenk				the ones marked with "*" in the list
585c609719bSwdenk				above.
586c609719bSwdenk
587c609719bSwdenk		If you don't define CONFIG_COMMANDS it defaults to
588c609719bSwdenk		CFG_CMD_DFL in include/cmd_confdefs.h. A board can
589c609719bSwdenk		override the default settings in the respective
590c609719bSwdenk		include file.
591c609719bSwdenk
592c609719bSwdenk		EXAMPLE: If you want all functions except of network
593c609719bSwdenk		support you can write:
594c609719bSwdenk
595c609719bSwdenk		#define CONFIG_COMMANDS (CFG_CMD_ALL & ~CFG_CMD_NET)
596c609719bSwdenk
597c609719bSwdenk
598c609719bSwdenk	Note:	Don't enable the "icache" and "dcache" commands
599c609719bSwdenk		(configuration option CFG_CMD_CACHE) unless you know
600c609719bSwdenk		what you (and your U-Boot users) are doing. Data
601c609719bSwdenk		cache cannot be enabled on systems like the 8xx or
602c609719bSwdenk		8260 (where accesses to the IMMR region must be
603c609719bSwdenk		uncached), and it cannot be disabled on all other
604c609719bSwdenk		systems where we (mis-) use the data cache to hold an
605c609719bSwdenk		initial stack and some data.
606c609719bSwdenk
607c609719bSwdenk
608c609719bSwdenk		XXX - this list needs to get updated!
609c609719bSwdenk
610c609719bSwdenk- Watchdog:
611c609719bSwdenk		CONFIG_WATCHDOG
612c609719bSwdenk		If this variable is defined, it enables watchdog
613c609719bSwdenk		support. There must support in the platform specific
614c609719bSwdenk		code for a watchdog. For the 8xx and 8260 CPUs, the
615c609719bSwdenk		SIU Watchdog feature is enabled in the SYPCR
616c609719bSwdenk		register.
617c609719bSwdenk
618c609719bSwdenk- Real-Time Clock:
619c609719bSwdenk
620c609719bSwdenk		When CFG_CMD_DATE is selected, the type of the RTC
621c609719bSwdenk		has to be selected, too. Define exactly one of the
622c609719bSwdenk		following options:
623c609719bSwdenk
624c609719bSwdenk		CONFIG_RTC_MPC8xx	- use internal RTC of MPC8xx
625c609719bSwdenk		CONFIG_RTC_PCF8563	- use Philips PCF8563 RTC
626c609719bSwdenk		CONFIG_RTC_MC146818	- use MC146818 RTC
627c609719bSwdenk		CONFIG_RTC_DS1337	- use Maxim, Inc. DS1337 RTC
628c609719bSwdenk
629c609719bSwdenk- Timestamp Support:
630c609719bSwdenk
631c609719bSwdenk		When CONFIG_TIMESTAMP is selected, the timestamp
632c609719bSwdenk		(date and time) of an image is printed by image
633c609719bSwdenk		commands like bootm or iminfo. This option is
634c609719bSwdenk		automatically enabled when you select CFG_CMD_DATE .
635c609719bSwdenk
636c609719bSwdenk- Partition Support:
637c609719bSwdenk		CONFIG_MAC_PARTITION and/or CONFIG_DOS_PARTITION
638c609719bSwdenk		and/or CONFIG_ISO_PARTITION
639c609719bSwdenk
640c609719bSwdenk		If IDE or SCSI support	is  enabled  (CFG_CMD_IDE  or
641c609719bSwdenk		CFG_CMD_SCSI) you must configure support for at least
642c609719bSwdenk		one partition type as well.
643c609719bSwdenk
644c609719bSwdenk- IDE Reset method:
645c609719bSwdenk		CONFIG_IDE_RESET_ROUTINE
646c609719bSwdenk
647c609719bSwdenk		Set this to define that instead of a reset Pin, the
648c609719bSwdenk		routine ide_set_reset(int idereset) will be used.
649c609719bSwdenk
650c609719bSwdenk- ATAPI Support:
651c609719bSwdenk		CONFIG_ATAPI
652c609719bSwdenk
653c609719bSwdenk		Set this to enable ATAPI support.
654c609719bSwdenk
655c609719bSwdenk- SCSI Support:
656c609719bSwdenk		At the moment only there is only support for the
657c609719bSwdenk		SYM53C8XX SCSI controller; define
658c609719bSwdenk		CONFIG_SCSI_SYM53C8XX to enable it.
659c609719bSwdenk
660c609719bSwdenk		CFG_SCSI_MAX_LUN [8], CFG_SCSI_MAX_SCSI_ID [7] and
661c609719bSwdenk		CFG_SCSI_MAX_DEVICE [CFG_SCSI_MAX_SCSI_ID *
662c609719bSwdenk		CFG_SCSI_MAX_LUN] can be adjusted to define the
663c609719bSwdenk		maximum numbers of LUNs, SCSI ID's and target
664c609719bSwdenk		devices.
665c609719bSwdenk		CFG_SCSI_SYM53C8XX_CCF to fix clock timing (80Mhz)
666c609719bSwdenk
667c609719bSwdenk- NETWORK Support (PCI):
668c609719bSwdenk		CONFIG_EEPRO100
669c609719bSwdenk		Support for Intel 82557/82559/82559ER chips.
670c609719bSwdenk		Optional CONFIG_EEPRO100_SROM_WRITE enables eeprom
671c609719bSwdenk		write routine for first time initialisation.
672c609719bSwdenk
673c609719bSwdenk		CONFIG_TULIP
674c609719bSwdenk		Support for Digital 2114x chips.
675c609719bSwdenk		Optional CONFIG_TULIP_SELECT_MEDIA for board specific
676c609719bSwdenk		modem chip initialisation (KS8761/QS6611).
677c609719bSwdenk
678c609719bSwdenk		CONFIG_NATSEMI
679c609719bSwdenk		Support for National dp83815 chips.
680c609719bSwdenk
681c609719bSwdenk		CONFIG_NS8382X
682c609719bSwdenk		Support for National dp8382[01] gigabit chips.
683c609719bSwdenk
684c609719bSwdenk- USB Support:
685c609719bSwdenk		At the moment only the UHCI host controller is
686c609719bSwdenk		supported (PIP405, MIP405); define
687c609719bSwdenk		CONFIG_USB_UHCI to enable it.
688c609719bSwdenk		define CONFIG_USB_KEYBOARD to enable the USB Keyboard
689c609719bSwdenk		end define CONFIG_USB_STORAGE to enable the USB
690c609719bSwdenk		storage devices.
691c609719bSwdenk		Note:
692c609719bSwdenk		Supported are USB Keyboards and USB Floppy drives
693c609719bSwdenk		(TEAC FD-05PUB).
694c609719bSwdenk
695c609719bSwdenk- Keyboard Support:
696c609719bSwdenk		CONFIG_ISA_KEYBOARD
697c609719bSwdenk
698c609719bSwdenk		Define this to enable standard (PC-Style) keyboard
699c609719bSwdenk		support
700c609719bSwdenk
701c609719bSwdenk		CONFIG_I8042_KBD
702c609719bSwdenk		Standard PC keyboard driver with US (is default) and
703c609719bSwdenk		GERMAN key layout (switch via environment 'keymap=de') support.
704c609719bSwdenk		Export function i8042_kbd_init, i8042_tstc and i8042_getc
705c609719bSwdenk		for cfb_console. Supports cursor blinking.
706c609719bSwdenk
707c609719bSwdenk- Video support:
708c609719bSwdenk		CONFIG_VIDEO
709c609719bSwdenk
710c609719bSwdenk		Define this to enable video support (for output to
711c609719bSwdenk		video).
712c609719bSwdenk
713c609719bSwdenk		CONFIG_VIDEO_CT69000
714c609719bSwdenk
715c609719bSwdenk		Enable Chips & Technologies 69000 Video chip
716c609719bSwdenk
717c609719bSwdenk		CONFIG_VIDEO_SMI_LYNXEM
718c609719bSwdenk		Enable Silicon Motion SMI 712/710/810 Video chip
719c609719bSwdenk		Videomode are selected via environment 'videomode' with
720c609719bSwdenk		standard LiLo mode numbers.
721c609719bSwdenk		Following modes are supported  (* is default):
722c609719bSwdenk
723c609719bSwdenk			    800x600  1024x768  1280x1024
724c609719bSwdenk	      256  (8bit)     303*      305       307
725c609719bSwdenk	    65536 (16bit)     314       317       31a
726c609719bSwdenk	16,7 Mill (24bit)     315       318       31b
727c609719bSwdenk		(i.e. setenv videomode 317; saveenv; reset;)
728c609719bSwdenk
729a6c7ad2fSwdenk		CONFIG_VIDEO_SED13806
730a6c7ad2fSwdenk		Enable Epson SED13806 driver. This driver supports 8bpp
731a6c7ad2fSwdenk		and 16bpp modes defined by CONFIG_VIDEO_SED13806_8BPP
732a6c7ad2fSwdenk		or CONFIG_VIDEO_SED13806_16BPP
733a6c7ad2fSwdenk
734a6c7ad2fSwdenk
735c609719bSwdenk- LCD Support:	CONFIG_LCD
736c609719bSwdenk
737c609719bSwdenk		Define this to enable LCD support (for output to LCD
738c609719bSwdenk		display); also select one of the supported displays
739c609719bSwdenk		by defining one of these:
740c609719bSwdenk
741c609719bSwdenk		CONFIG_NEC_NL6648AC33:
742c609719bSwdenk
743c609719bSwdenk			NEC NL6648AC33-18. Active, color, single scan.
744c609719bSwdenk
745c609719bSwdenk		CONFIG_NEC_NL6648BC20
746c609719bSwdenk
747c609719bSwdenk			NEC NL6648BC20-08. 6.5", 640x480.
748c609719bSwdenk			Active, color, single scan.
749c609719bSwdenk
750c609719bSwdenk		CONFIG_SHARP_16x9
751c609719bSwdenk
752c609719bSwdenk			Sharp 320x240. Active, color, single scan.
753c609719bSwdenk			It isn't 16x9, and I am not sure what it is.
754c609719bSwdenk
755c609719bSwdenk		CONFIG_SHARP_LQ64D341
756c609719bSwdenk
757c609719bSwdenk			Sharp LQ64D341 display, 640x480.
758c609719bSwdenk			Active, color, single scan.
759c609719bSwdenk
760c609719bSwdenk		CONFIG_HLD1045
761c609719bSwdenk
762c609719bSwdenk			HLD1045 display, 640x480.
763c609719bSwdenk			Active, color, single scan.
764c609719bSwdenk
765c609719bSwdenk		CONFIG_OPTREX_BW
766c609719bSwdenk
767c609719bSwdenk			Optrex	 CBL50840-2 NF-FW 99 22 M5
768c609719bSwdenk			or
769c609719bSwdenk			Hitachi	 LMG6912RPFC-00T
770c609719bSwdenk			or
771c609719bSwdenk			Hitachi	 SP14Q002
772c609719bSwdenk
773c609719bSwdenk			320x240. Black & white.
774c609719bSwdenk
775c609719bSwdenk		Normally display is black on white background; define
776c609719bSwdenk		CFG_WHITE_ON_BLACK to get it inverted.
777c609719bSwdenk
778c609719bSwdenk- Ethernet address:
779c609719bSwdenk		CONFIG_ETHADDR
780c609719bSwdenk		CONFIG_ETH2ADDR
781c609719bSwdenk		CONFIG_ETH3ADDR
782c609719bSwdenk
783c609719bSwdenk		Define a default value for ethernet address to use
784c609719bSwdenk		for the respective ethernet interface, in case this
785c609719bSwdenk		is not determined automatically.
786c609719bSwdenk
787c609719bSwdenk- IP address:
788c609719bSwdenk		CONFIG_IPADDR
789c609719bSwdenk
790c609719bSwdenk		Define a default value for the IP address to use for
791c609719bSwdenk		the default ethernet interface, in case this is not
792c609719bSwdenk		determined through e.g. bootp.
793c609719bSwdenk
794c609719bSwdenk- Server IP address:
795c609719bSwdenk		CONFIG_SERVERIP
796c609719bSwdenk
797c609719bSwdenk		Defines a default value for theIP address of a TFTP
798c609719bSwdenk		server to contact when using the "tftboot" command.
799c609719bSwdenk
800c609719bSwdenk- BOOTP Recovery Mode:
801c609719bSwdenk		CONFIG_BOOTP_RANDOM_DELAY
802c609719bSwdenk
803c609719bSwdenk		If you have many targets in a network that try to
804c609719bSwdenk		boot using BOOTP, you may want to avoid that all
805c609719bSwdenk		systems send out BOOTP requests at precisely the same
806c609719bSwdenk		moment (which would happen for instance at recovery
807c609719bSwdenk		from a power failure, when all systems will try to
808c609719bSwdenk		boot, thus flooding the BOOTP server. Defining
809c609719bSwdenk		CONFIG_BOOTP_RANDOM_DELAY causes a random delay to be
810c609719bSwdenk		inserted before sending out BOOTP requests. The
811c609719bSwdenk		following delays are insterted then:
812c609719bSwdenk
813c609719bSwdenk		1st BOOTP request:	delay 0 ... 1 sec
814c609719bSwdenk		2nd BOOTP request:	delay 0 ... 2 sec
815c609719bSwdenk		3rd BOOTP request:	delay 0 ... 4 sec
816c609719bSwdenk		4th and following
817c609719bSwdenk		BOOTP requests:		delay 0 ... 8 sec
818c609719bSwdenk
819c609719bSwdenk- Status LED:	CONFIG_STATUS_LED
820c609719bSwdenk
821c609719bSwdenk		Several configurations allow to display the current
822c609719bSwdenk		status using a LED. For instance, the LED will blink
823c609719bSwdenk		fast while running U-Boot code, stop blinking as
824c609719bSwdenk		soon as a reply to a BOOTP request was received, and
825c609719bSwdenk		start blinking slow once the Linux kernel is running
826c609719bSwdenk		(supported by a status LED driver in the Linux
827c609719bSwdenk		kernel). Defining CONFIG_STATUS_LED enables this
828c609719bSwdenk		feature in U-Boot.
829c609719bSwdenk
830c609719bSwdenk- CAN Support:	CONFIG_CAN_DRIVER
831c609719bSwdenk
832c609719bSwdenk		Defining CONFIG_CAN_DRIVER enables CAN driver support
833c609719bSwdenk		on those systems that support this (optional)
834c609719bSwdenk		feature, like the TQM8xxL modules.
835c609719bSwdenk
836c609719bSwdenk- I2C Support:	CONFIG_HARD_I2C | CONFIG_SOFT_I2C
837c609719bSwdenk
838c609719bSwdenk		Enables I2C serial bus commands.  If this is selected,
839c609719bSwdenk		either CONFIG_HARD_I2C or CONFIG_SOFT_I2C must be defined
840c609719bSwdenk		to include the appropriate I2C driver.
841c609719bSwdenk
842c609719bSwdenk		See also: common/cmd_i2c.c for a description of the
843c609719bSwdenk		command line interface.
844c609719bSwdenk
845c609719bSwdenk
846c609719bSwdenk		CONFIG_HARD_I2C
847c609719bSwdenk
848c609719bSwdenk		Selects the CPM hardware driver for I2C.
849c609719bSwdenk
850c609719bSwdenk		CONFIG_SOFT_I2C
851c609719bSwdenk
852c609719bSwdenk		Use software (aka bit-banging) driver instead of CPM
853c609719bSwdenk		or similar hardware support for I2C.  This is configured
854c609719bSwdenk		via the following defines.
855c609719bSwdenk
856c609719bSwdenk		I2C_INIT
857c609719bSwdenk
858c609719bSwdenk		(Optional). Any commands necessary to enable I2C
859c609719bSwdenk		controller or configure ports.
860c609719bSwdenk
861c609719bSwdenk		I2C_PORT
862c609719bSwdenk
863c609719bSwdenk		(Only for MPC8260 CPU). The I/O port to use (the code
864c609719bSwdenk		assumes both bits are on the same port). Valid values
865c609719bSwdenk		are 0..3 for ports A..D.
866c609719bSwdenk
867c609719bSwdenk		I2C_ACTIVE
868c609719bSwdenk
869c609719bSwdenk		The code necessary to make the I2C data line active
870c609719bSwdenk		(driven).  If the data line is open collector, this
871c609719bSwdenk		define can be null.
872c609719bSwdenk
873c609719bSwdenk		I2C_TRISTATE
874c609719bSwdenk
875c609719bSwdenk		The code necessary to make the I2C data line tri-stated
876c609719bSwdenk		(inactive).  If the data line is open collector, this
877c609719bSwdenk		define can be null.
878c609719bSwdenk
879c609719bSwdenk		I2C_READ
880c609719bSwdenk
881c609719bSwdenk		Code that returns TRUE if the I2C data line is high,
882c609719bSwdenk		FALSE if it is low.
883c609719bSwdenk
884c609719bSwdenk		I2C_SDA(bit)
885c609719bSwdenk
886c609719bSwdenk		If <bit> is TRUE, sets the I2C data line high. If it
887c609719bSwdenk		is FALSE, it clears it (low).
888c609719bSwdenk
889c609719bSwdenk		I2C_SCL(bit)
890c609719bSwdenk
891c609719bSwdenk		If <bit> is TRUE, sets the I2C clock line high. If it
892c609719bSwdenk		is FALSE, it clears it (low).
893c609719bSwdenk
894c609719bSwdenk		I2C_DELAY
895c609719bSwdenk
896c609719bSwdenk		This delay is invoked four times per clock cycle so this
897c609719bSwdenk		controls the rate of data transfer.  The data rate thus
898c609719bSwdenk		is 1 / (I2C_DELAY * 4).
899c609719bSwdenk
900c609719bSwdenk- SPI Support:	CONFIG_SPI
901c609719bSwdenk
902c609719bSwdenk		Enables SPI driver (so far only tested with
903c609719bSwdenk		SPI EEPROM, also an instance works with Crystal A/D and
904c609719bSwdenk		D/As on the SACSng board)
905c609719bSwdenk
906c609719bSwdenk		CONFIG_SPI_X
907c609719bSwdenk
908c609719bSwdenk		Enables extended (16-bit) SPI EEPROM addressing.
909c609719bSwdenk		(symmetrical to CONFIG_I2C_X)
910c609719bSwdenk
911c609719bSwdenk		CONFIG_SOFT_SPI
912c609719bSwdenk
913c609719bSwdenk		Enables a software (bit-bang) SPI driver rather than
914c609719bSwdenk		using hardware support. This is a general purpose
915c609719bSwdenk		driver that only requires three general I/O port pins
916c609719bSwdenk		(two outputs, one input) to function. If this is
917c609719bSwdenk		defined, the board configuration must define several
918c609719bSwdenk		SPI configuration items (port pins to use, etc). For
919c609719bSwdenk		an example, see include/configs/sacsng.h.
920c609719bSwdenk
921c609719bSwdenk- FPGA Support: CONFIG_FPGA_COUNT
922c609719bSwdenk
923c609719bSwdenk		Specify the number of FPGA devices to support.
924c609719bSwdenk
925c609719bSwdenk		CONFIG_FPGA
926c609719bSwdenk
927c609719bSwdenk		Used to specify the types of FPGA devices. For
928c609719bSwdenk		example,
929c609719bSwdenk 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
930c609719bSwdenk
931c609719bSwdenk 		CFG_FPGA_PROG_FEEDBACK
932c609719bSwdenk
933c609719bSwdenk		Enable printing of hash marks during FPGA
934c609719bSwdenk		configuration.
935c609719bSwdenk
936c609719bSwdenk		CFG_FPGA_CHECK_BUSY
937c609719bSwdenk
938c609719bSwdenk		Enable checks on FPGA configuration interface busy
939c609719bSwdenk		status by the configuration function. This option
940c609719bSwdenk		will require a board or device specific function to
941c609719bSwdenk		be written.
942c609719bSwdenk
943c609719bSwdenk		CONFIG_FPGA_DELAY
944c609719bSwdenk
945c609719bSwdenk		If defined, a function that provides delays in the
946c609719bSwdenk		FPGA configuration driver.
947c609719bSwdenk
948c609719bSwdenk		CFG_FPGA_CHECK_CTRLC
949c609719bSwdenk
950c609719bSwdenk		Allow Control-C to interrupt FPGA configuration
951c609719bSwdenk
952c609719bSwdenk		CFG_FPGA_CHECK_ERROR
953c609719bSwdenk
954c609719bSwdenk		Check for configuration errors during FPGA bitfile
955c609719bSwdenk		loading. For example, abort during Virtex II
956c609719bSwdenk		configuration if the INIT_B line goes low (which
957c609719bSwdenk		indicated a CRC error).
958c609719bSwdenk
959c609719bSwdenk		CFG_FPGA_WAIT_INIT
960c609719bSwdenk
961c609719bSwdenk		Maximum time to wait for the INIT_B line to deassert
962c609719bSwdenk		after PROB_B has been deasserted during a Virtex II
963c609719bSwdenk		FPGA configuration sequence. The default time is 500 mS.
964c609719bSwdenk
965c609719bSwdenk		CFG_FPGA_WAIT_BUSY
966c609719bSwdenk
967c609719bSwdenk		Maximum time to wait for BUSY to deassert during
968c609719bSwdenk		Virtex II FPGA configuration. The default is 5 mS.
969c609719bSwdenk
970c609719bSwdenk		CFG_FPGA_WAIT_CONFIG
971c609719bSwdenk
972c609719bSwdenk		Time to wait after FPGA configuration. The default is
973c609719bSwdenk		200 mS.
974c609719bSwdenk
975c609719bSwdenk- FPGA Support:	CONFIG_FPGA_COUNT
976c609719bSwdenk
977c609719bSwdenk 		Specify the number of FPGA devices to support.
978c609719bSwdenk
979c609719bSwdenk 		CONFIG_FPGA
980c609719bSwdenk
981c609719bSwdenk 		Used to specify the types of FPGA devices.  For example,
982c609719bSwdenk 		#define CONFIG_FPGA  CFG_XILINX_VIRTEX2
983c609719bSwdenk
984c609719bSwdenk 		CFG_FPGA_PROG_FEEDBACK
985c609719bSwdenk
986c609719bSwdenk 		Enable printing of hash marks during FPGA configuration.
987c609719bSwdenk
988c609719bSwdenk		CFG_FPGA_CHECK_BUSY
989c609719bSwdenk
990c609719bSwdenk		Enable checks on FPGA configuration interface busy
991c609719bSwdenk		status by the configuration function. This option
992c609719bSwdenk		will require a board or device specific function to
993c609719bSwdenk		be written.
994c609719bSwdenk
995c609719bSwdenk		CONFIG_FPGA_DELAY
996c609719bSwdenk
997c609719bSwdenk		If defined, a function that provides delays in the FPGA
998c609719bSwdenk		configuration driver.
999c609719bSwdenk
1000c609719bSwdenk		CFG_FPGA_CHECK_CTRLC
1001c609719bSwdenk		Allow Control-C to interrupt FPGA configuration
1002c609719bSwdenk
1003c609719bSwdenk		CFG_FPGA_CHECK_ERROR
1004c609719bSwdenk
1005c609719bSwdenk		Check for configuration errors during FPGA bitfile
1006c609719bSwdenk		loading. For example, abort during Virtex II
1007c609719bSwdenk		configuration if the INIT_B line goes low (which
1008c609719bSwdenk		indicated a CRC error).
1009c609719bSwdenk
1010c609719bSwdenk		CFG_FPGA_WAIT_INIT
1011c609719bSwdenk
1012c609719bSwdenk		Maximum time to wait for the INIT_B line to deassert
1013c609719bSwdenk		after PROB_B has been deasserted during a Virtex II
1014c609719bSwdenk		FPGA configuration sequence. The default time is 500
1015c609719bSwdenk		mS.
1016c609719bSwdenk
1017c609719bSwdenk		CFG_FPGA_WAIT_BUSY
1018c609719bSwdenk
1019c609719bSwdenk		Maximum time to wait for BUSY to deassert during
1020c609719bSwdenk		Virtex II FPGA configuration. The default is 5 mS.
1021c609719bSwdenk
1022c609719bSwdenk		CFG_FPGA_WAIT_CONFIG
1023c609719bSwdenk
1024c609719bSwdenk		Time to wait after FPGA configuration. The default is
1025c609719bSwdenk		200 mS.
1026c609719bSwdenk
1027c609719bSwdenk- Configuration Management:
1028c609719bSwdenk		CONFIG_IDENT_STRING
1029c609719bSwdenk
1030c609719bSwdenk		If defined, this string will be added to the U-Boot
1031c609719bSwdenk		version information (U_BOOT_VERSION)
1032c609719bSwdenk
1033c609719bSwdenk- Vendor Parameter Protection:
1034c609719bSwdenk
1035c609719bSwdenk		U-Boot considers the values of the environment
1036c609719bSwdenk		variables "serial#" (Board Serial Number) and
1037c609719bSwdenk		"ethaddr" (Ethernet Address) to bb parameters that
1038c609719bSwdenk		are set once by the board vendor / manufacturer, and
1039c609719bSwdenk		protects these variables from casual modification by
1040c609719bSwdenk		the user. Once set, these variables are read-only,
1041c609719bSwdenk		and write or delete attempts are rejected. You can
1042c609719bSwdenk		change this behviour:
1043c609719bSwdenk
1044c609719bSwdenk		If CONFIG_ENV_OVERWRITE is #defined in your config
1045c609719bSwdenk		file, the write protection for vendor parameters is
1046c609719bSwdenk		completely disabled. Anybody can change or delte
1047c609719bSwdenk		these parameters.
1048c609719bSwdenk
1049c609719bSwdenk		Alternatively, if you #define _both_ CONFIG_ETHADDR
1050c609719bSwdenk		_and_ CONFIG_OVERWRITE_ETHADDR_ONCE, a default
1051c609719bSwdenk		ethernet address is installed in the environment,
1052c609719bSwdenk		which can be changed exactly ONCE by the user. [The
1053c609719bSwdenk		serial# is unaffected by this, i. e. it remains
1054c609719bSwdenk		read-only.]
1055c609719bSwdenk
1056c609719bSwdenk- Protected RAM:
1057c609719bSwdenk		CONFIG_PRAM
1058c609719bSwdenk
1059c609719bSwdenk		Define this variable to enable the reservation of
1060c609719bSwdenk		"protected RAM", i. e. RAM which is not overwritten
1061c609719bSwdenk		by U-Boot. Define CONFIG_PRAM to hold the number of
1062c609719bSwdenk		kB you want to reserve for pRAM. You can overwrite
1063c609719bSwdenk		this default value by defining an environment
1064c609719bSwdenk		variable "pram" to the number of kB you want to
1065c609719bSwdenk		reserve. Note that the board info structure will
1066c609719bSwdenk		still show the full amount of RAM. If pRAM is
1067c609719bSwdenk		reserved, a new environment variable "mem" will
1068c609719bSwdenk		automatically be defined to hold the amount of
1069c609719bSwdenk		remaining RAM in a form that can be passed as boot
1070c609719bSwdenk		argument to Linux, for instance like that:
1071c609719bSwdenk
1072c609719bSwdenk			setenv bootargs ... mem=\$(mem)
1073c609719bSwdenk			saveenv
1074c609719bSwdenk
1075c609719bSwdenk		This way you can tell Linux not to use this memory,
1076c609719bSwdenk		either, which results in a memory region that will
1077c609719bSwdenk		not be affected by reboots.
1078c609719bSwdenk
1079c609719bSwdenk		*WARNING* If your board configuration uses automatic
1080c609719bSwdenk		detection of the RAM size, you must make sure that
1081c609719bSwdenk		this memory test is non-destructive. So far, the
1082c609719bSwdenk		following board configurations are known to be
1083c609719bSwdenk		"pRAM-clean":
1084c609719bSwdenk
1085c609719bSwdenk			ETX094, IVMS8, IVML24, SPD8xx, TQM8xxL,
1086c609719bSwdenk			HERMES, IP860, RPXlite, LWMON, LANTEC,
1087c609719bSwdenk			PCU_E, FLAGADM, TQM8260
1088c609719bSwdenk
1089c609719bSwdenk- Error Recovery:
1090c609719bSwdenk		CONFIG_PANIC_HANG
1091c609719bSwdenk
1092c609719bSwdenk		Define this variable to stop the system in case of a
1093c609719bSwdenk		fatal error, so that you have to reset it manually.
1094c609719bSwdenk		This is probably NOT a good idea for an embedded
1095c609719bSwdenk		system where you want to system to reboot
1096c609719bSwdenk		automatically as fast as possible, but it may be
1097c609719bSwdenk		useful during development since you can try to debug
1098c609719bSwdenk		the conditions that lead to the situation.
1099c609719bSwdenk
1100c609719bSwdenk		CONFIG_NET_RETRY_COUNT
1101c609719bSwdenk
1102c609719bSwdenk		This variable defines the number of retries for
1103c609719bSwdenk		network operations like ARP, RARP, TFTP, or BOOTP
1104c609719bSwdenk		before giving up the operation. If not defined, a
1105c609719bSwdenk		default value of 5 is used.
1106c609719bSwdenk
1107c609719bSwdenk- Command Interpreter:
1108c609719bSwdenk		CFG_HUSH_PARSER
1109c609719bSwdenk
1110c609719bSwdenk		Define this variable to enable the "hush" shell (from
1111c609719bSwdenk		Busybox) as command line interpreter, thus enabling
1112c609719bSwdenk		powerful command line syntax like
1113c609719bSwdenk		if...then...else...fi conditionals or `&&' and '||'
1114c609719bSwdenk		constructs ("shell scripts").
1115c609719bSwdenk
1116c609719bSwdenk		If undefined, you get the old, much simpler behaviour
1117c609719bSwdenk		with a somewhat smaller memory footprint.
1118c609719bSwdenk
1119c609719bSwdenk
1120c609719bSwdenk		CFG_PROMPT_HUSH_PS2
1121c609719bSwdenk
1122c609719bSwdenk		This defines the secondary prompt string, which is
1123c609719bSwdenk		printed when the command interpreter needs more input
1124c609719bSwdenk		to complete a command. Usually "> ".
1125c609719bSwdenk
1126c609719bSwdenk	Note:
1127c609719bSwdenk
1128c609719bSwdenk		In the current implementation, the local variables
1129c609719bSwdenk		space and global environment variables space are
1130c609719bSwdenk		separated. Local variables are those you define by
1131c609719bSwdenk		simply typing like `name=value'. To access a local
1132c609719bSwdenk		variable later on, you have write `$name' or
1133c609719bSwdenk		`${name}'; variable directly by typing say `$name' at
1134c609719bSwdenk		the command prompt.
1135c609719bSwdenk
1136c609719bSwdenk		Global environment variables are those you use
1137c609719bSwdenk		setenv/printenv to work with. To run a command stored
1138c609719bSwdenk		in such a variable, you need to use the run command,
1139c609719bSwdenk		and you must not use the '$' sign to access them.
1140c609719bSwdenk
1141c609719bSwdenk		To store commands and special characters in a
1142c609719bSwdenk		variable, please use double quotation marks
1143c609719bSwdenk		surrounding the whole text of the variable, instead
1144c609719bSwdenk		of the backslashes before semicolons and special
1145c609719bSwdenk		symbols.
1146c609719bSwdenk
1147c609719bSwdenk- Default Environment
1148c609719bSwdenk		CONFIG_EXTRA_ENV_SETTINGS
1149c609719bSwdenk
1150c609719bSwdenk		Define this to contain any number of null terminated
1151c609719bSwdenk		strings (variable = value pairs) that will be part of
1152c609719bSwdenk		the default enviroment compiled into the boot image.
11532262cfeeSwdenk
1154c609719bSwdenk		For example, place something like this in your
1155c609719bSwdenk		board's config file:
1156c609719bSwdenk
1157c609719bSwdenk		#define CONFIG_EXTRA_ENV_SETTINGS \
1158c609719bSwdenk			"myvar1=value1\0" \
1159c609719bSwdenk			"myvar2=value2\0"
1160c609719bSwdenk
1161c609719bSwdenk		Warning: This method is based on knowledge about the
1162c609719bSwdenk		internal format how the environment is stored by the
11632262cfeeSwdenk		U-Boot code. This is NOT an official, exported
1164c609719bSwdenk		interface! Although it is unlikely that this format
11652262cfeeSwdenk		will change soon, but there is no guarantee either.
1166c609719bSwdenk		You better know what you are doing here.
1167c609719bSwdenk
1168c609719bSwdenk		Note: overly (ab)use of the default environment is
1169c609719bSwdenk		discouraged. Make sure to check other ways to preset
1170c609719bSwdenk		the environment like the autoscript function or the
1171c609719bSwdenk		boot command first.
1172c609719bSwdenk
1173c609719bSwdenk- Show boot progress
1174c609719bSwdenk		CONFIG_SHOW_BOOT_PROGRESS
1175c609719bSwdenk
1176c609719bSwdenk		Defining this option allows to add some board-
1177c609719bSwdenk		specific code (calling a user-provided function
1178c609719bSwdenk		"show_boot_progress(int)") that enables you to show
1179c609719bSwdenk		the system's boot progress on some display (for
1180c609719bSwdenk		example, some LED's) on your board. At the moment,
1181c609719bSwdenk		the following checkpoints are implemented:
1182c609719bSwdenk
1183c609719bSwdenk  Arg	Where			When
1184c609719bSwdenk    1	common/cmd_bootm.c	before attempting to boot an image
1185c609719bSwdenk   -1	common/cmd_bootm.c	Image header has bad     magic number
1186c609719bSwdenk    2	common/cmd_bootm.c	Image header has correct magic number
1187c609719bSwdenk   -2	common/cmd_bootm.c	Image header has bad     checksum
1188c609719bSwdenk    3	common/cmd_bootm.c	Image header has correct checksum
1189c609719bSwdenk   -3	common/cmd_bootm.c	Image data   has bad     checksum
1190c609719bSwdenk    4	common/cmd_bootm.c	Image data   has correct checksum
1191c609719bSwdenk   -4	common/cmd_bootm.c	Image is for unsupported architecture
1192c609719bSwdenk    5	common/cmd_bootm.c	Architecture check OK
1193c609719bSwdenk   -5	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1194c609719bSwdenk    6	common/cmd_bootm.c	Image Type check OK
1195c609719bSwdenk   -6	common/cmd_bootm.c	gunzip uncompression error
1196c609719bSwdenk   -7	common/cmd_bootm.c	Unimplemented compression type
1197c609719bSwdenk    7	common/cmd_bootm.c	Uncompression OK
1198c609719bSwdenk   -8	common/cmd_bootm.c	Wrong Image Type (not kernel, multi, standalone)
1199c609719bSwdenk    8	common/cmd_bootm.c	Image Type check OK
1200c609719bSwdenk   -9	common/cmd_bootm.c	Unsupported OS (not Linux, BSD, VxWorks, QNX)
1201c609719bSwdenk    9	common/cmd_bootm.c	Start initial ramdisk verification
1202c609719bSwdenk  -10	common/cmd_bootm.c	Ramdisk header has bad     magic number
1203c609719bSwdenk  -11	common/cmd_bootm.c	Ramdisk header has bad     checksum
1204c609719bSwdenk   10	common/cmd_bootm.c	Ramdisk header is OK
1205c609719bSwdenk  -12	common/cmd_bootm.c	Ramdisk data   has bad     checksum
1206c609719bSwdenk   11	common/cmd_bootm.c	Ramdisk data   has correct checksum
1207c609719bSwdenk   12	common/cmd_bootm.c	Ramdisk verification complete, start loading
1208c609719bSwdenk  -13	common/cmd_bootm.c	Wrong Image Type (not PPC Linux Ramdisk)
1209c609719bSwdenk   13	common/cmd_bootm.c	Start multifile image verification
1210c609719bSwdenk   14	common/cmd_bootm.c	No initial ramdisk, no multifile, continue.
1211c609719bSwdenk   15	common/cmd_bootm.c	All preparation done, transferring control to OS
1212c609719bSwdenk
1213c609719bSwdenk   -1	common/cmd_doc.c	Bad usage of "doc" command
1214c609719bSwdenk   -1	common/cmd_doc.c	No boot device
1215c609719bSwdenk   -1	common/cmd_doc.c	Unknown Chip ID on boot device
1216c609719bSwdenk   -1	common/cmd_doc.c	Read Error on boot device
1217c609719bSwdenk   -1	common/cmd_doc.c	Image header has bad magic number
1218c609719bSwdenk
1219c609719bSwdenk   -1	common/cmd_ide.c	Bad usage of "ide" command
1220c609719bSwdenk   -1	common/cmd_ide.c	No boot device
1221c609719bSwdenk   -1	common/cmd_ide.c	Unknown boot device
1222c609719bSwdenk   -1	common/cmd_ide.c	Unknown partition table
1223c609719bSwdenk   -1	common/cmd_ide.c	Invalid partition type
1224c609719bSwdenk   -1	common/cmd_ide.c	Read Error on boot device
1225c609719bSwdenk   -1	common/cmd_ide.c	Image header has bad magic number
1226c609719bSwdenk
1227c609719bSwdenk   -1	common/cmd_nvedit.c	Environment not changable, but has bad CRC
1228c609719bSwdenk
1229c609719bSwdenk
1230c609719bSwdenkModem Support:
1231c609719bSwdenk--------------
1232c609719bSwdenk
1233c609719bSwdenk[so far only for SMDK2400 board]
1234c609719bSwdenk
1235c609719bSwdenk- Modem support endable:
1236c609719bSwdenk		CONFIG_MODEM_SUPPORT
1237c609719bSwdenk
1238c609719bSwdenk- RTS/CTS Flow control enable:
1239c609719bSwdenk		CONFIG_HWFLOW
1240c609719bSwdenk
1241c609719bSwdenk- Modem debug support:
1242c609719bSwdenk		CONFIG_MODEM_SUPPORT_DEBUG
1243c609719bSwdenk
1244c609719bSwdenk		Enables debugging stuff (char screen[1024], dbg())
1245c609719bSwdenk		for modem support. Useful only with BDI2000.
1246c609719bSwdenk
1247c609719bSwdenk- General:
1248c609719bSwdenk
1249c609719bSwdenk		In the target system modem support is enabled when a
1250c609719bSwdenk		specific key (key combination) is pressed during
1251c609719bSwdenk		power-on. Otherwise U-Boot will boot normally
1252c609719bSwdenk		(autoboot). The key_pressed() fuction is called from
1253c609719bSwdenk		board_init(). Currently key_pressed() is a dummy
1254c609719bSwdenk		function, returning 1 and thus enabling modem
1255c609719bSwdenk		initialization.
1256c609719bSwdenk
1257c609719bSwdenk		If there are no modem init strings in the
1258c609719bSwdenk		environment, U-Boot proceed to autoboot; the
1259c609719bSwdenk		previous output (banner, info printfs) will be
1260c609719bSwdenk		supressed, though.
1261c609719bSwdenk
1262c609719bSwdenk		See also: doc/README.Modem
1263c609719bSwdenk
1264c609719bSwdenk
1265c609719bSwdenk
1266c609719bSwdenk
1267c609719bSwdenkConfiguration Settings:
1268c609719bSwdenk-----------------------
1269c609719bSwdenk
1270c609719bSwdenk- CFG_LONGHELP: Defined when you want long help messages included;
1271c609719bSwdenk		undefine this when you're short of memory.
1272c609719bSwdenk
1273c609719bSwdenk- CFG_PROMPT:	This is what U-Boot prints on the console to
1274c609719bSwdenk		prompt for user input.
1275c609719bSwdenk
1276c609719bSwdenk- CFG_CBSIZE:	Buffer size for input from the Console
1277c609719bSwdenk
1278c609719bSwdenk- CFG_PBSIZE:	Buffer size for Console output
1279c609719bSwdenk
1280c609719bSwdenk- CFG_MAXARGS:	max. Number of arguments accepted for monitor commands
1281c609719bSwdenk
1282c609719bSwdenk- CFG_BARGSIZE: Buffer size for Boot Arguments which are passed to
1283c609719bSwdenk		the application (usually a Linux kernel) when it is
1284c609719bSwdenk		booted
1285c609719bSwdenk
1286c609719bSwdenk- CFG_BAUDRATE_TABLE:
1287c609719bSwdenk		List of legal baudrate settings for this board.
1288c609719bSwdenk
1289c609719bSwdenk- CFG_CONSOLE_INFO_QUIET
1290c609719bSwdenk 		Suppress display of console information at boot.
1291c609719bSwdenk
1292c609719bSwdenk- CFG_CONSOLE_IS_IN_ENV
1293c609719bSwdenk 		If the board specific function
1294c609719bSwdenk 			extern int overwrite_console (void);
1295c609719bSwdenk 		returns 1, the stdin, stderr and stdout are switched to the
1296c609719bSwdenk		serial port, else the settings in the environment are used.
1297c609719bSwdenk
1298c609719bSwdenk- CFG_CONSOLE_OVERWRITE_ROUTINE
1299c609719bSwdenk 		Enable the call to overwrite_console().
1300c609719bSwdenk
1301c609719bSwdenk- CFG_CONSOLE_ENV_OVERWRITE
1302c609719bSwdenk		Enable overwrite of previous console environment settings.
1303c609719bSwdenk
1304c609719bSwdenk- CFG_MEMTEST_START, CFG_MEMTEST_END:
1305c609719bSwdenk		Begin and End addresses of the area used by the
1306c609719bSwdenk		simple memory test.
1307c609719bSwdenk
1308c609719bSwdenk- CFG_ALT_MEMTEST:
1309c609719bSwdenk 		Enable an alternate, more extensive memory test.
1310c609719bSwdenk
1311c609719bSwdenk- CFG_TFTP_LOADADDR:
1312c609719bSwdenk		Default load address for network file downloads
1313c609719bSwdenk
1314c609719bSwdenk- CFG_LOADS_BAUD_CHANGE:
1315c609719bSwdenk		Enable temporary baudrate change while serial download
1316c609719bSwdenk
1317c609719bSwdenk- CFG_SDRAM_BASE:
1318c609719bSwdenk		Physical start address of SDRAM. _Must_ be 0 here.
1319c609719bSwdenk
1320c609719bSwdenk- CFG_MBIO_BASE:
1321c609719bSwdenk		Physical start address of Motherboard I/O (if using a
1322c609719bSwdenk		Cogent motherboard)
1323c609719bSwdenk
1324c609719bSwdenk- CFG_FLASH_BASE:
1325c609719bSwdenk		Physical start address of Flash memory.
1326c609719bSwdenk
1327c609719bSwdenk- CFG_MONITOR_BASE:
1328c609719bSwdenk		Physical start address of boot monitor code (set by
1329c609719bSwdenk		make config files to be same as the text base address
1330c609719bSwdenk		(TEXT_BASE) used when linking) - same as
1331c609719bSwdenk		CFG_FLASH_BASE when booting from flash.
1332c609719bSwdenk
1333c609719bSwdenk- CFG_MONITOR_LEN:
1334c609719bSwdenk		Size of memory reserved for monitor code
1335c609719bSwdenk
1336c609719bSwdenk- CFG_MALLOC_LEN:
1337c609719bSwdenk		Size of DRAM reserved for malloc() use.
1338c609719bSwdenk
1339c609719bSwdenk- CFG_BOOTMAPSZ:
1340c609719bSwdenk		Maximum size of memory mapped by the startup code of
1341c609719bSwdenk		the Linux kernel; all data that must be processed by
1342c609719bSwdenk		the Linux kernel (bd_info, boot arguments, eventually
1343c609719bSwdenk		initrd image) must be put below this limit.
1344c609719bSwdenk
1345c609719bSwdenk- CFG_MAX_FLASH_BANKS:
1346c609719bSwdenk		Max number of Flash memory banks
1347c609719bSwdenk
1348c609719bSwdenk- CFG_MAX_FLASH_SECT:
1349c609719bSwdenk		Max number of sectors on a Flash chip
1350c609719bSwdenk
1351c609719bSwdenk- CFG_FLASH_ERASE_TOUT:
1352c609719bSwdenk		Timeout for Flash erase operations (in ms)
1353c609719bSwdenk
1354c609719bSwdenk- CFG_FLASH_WRITE_TOUT:
1355c609719bSwdenk		Timeout for Flash write operations (in ms)
1356c609719bSwdenk
1357c609719bSwdenk- CFG_DIRECT_FLASH_TFTP:
1358c609719bSwdenk
1359c609719bSwdenk		Enable TFTP transfers directly to flash memory;
1360c609719bSwdenk		without this option such a download has to be
1361c609719bSwdenk		performed in two steps: (1) download to RAM, and (2)
1362c609719bSwdenk		copy from RAM to flash.
1363c609719bSwdenk
1364c609719bSwdenk		The two-step approach is usually more reliable, since
1365c609719bSwdenk		you can check if the download worked before you erase
1366c609719bSwdenk		the flash, but in some situations (when sytem RAM is
1367c609719bSwdenk		too limited to allow for a tempory copy of the
1368c609719bSwdenk		downloaded image) this option may be very useful.
1369c609719bSwdenk
1370c609719bSwdenk- CFG_FLASH_CFI:
1371c609719bSwdenk		Define if the flash driver uses extra elements in the
1372c609719bSwdenk		common flash structure for storing flash geometry
1373c609719bSwdenk
1374c609719bSwdenkThe following definitions that deal with the placement and management
1375c609719bSwdenkof environment data (variable area); in general, we support the
1376c609719bSwdenkfollowing configurations:
1377c609719bSwdenk
1378c609719bSwdenk- CFG_ENV_IS_IN_FLASH:
1379c609719bSwdenk
1380c609719bSwdenk	Define this if the environment is in flash memory.
1381c609719bSwdenk
1382c609719bSwdenk	a) The environment occupies one whole flash sector, which is
1383c609719bSwdenk	   "embedded" in the text segment with the U-Boot code. This
1384c609719bSwdenk	   happens usually with "bottom boot sector" or "top boot
1385c609719bSwdenk	   sector" type flash chips, which have several smaller
1386c609719bSwdenk	   sectors at the start or the end. For instance, such a
1387c609719bSwdenk	   layout can have sector sizes of 8, 2x4, 16, Nx32 kB. In
1388c609719bSwdenk	   such a case you would place the environment in one of the
1389c609719bSwdenk	   4 kB sectors - with U-Boot code before and after it. With
1390c609719bSwdenk	   "top boot sector" type flash chips, you would put the
1391c609719bSwdenk	   environment in one of the last sectors, leaving a gap
1392c609719bSwdenk	   between U-Boot and the environment.
1393c609719bSwdenk
1394c609719bSwdenk	- CFG_ENV_OFFSET:
1395c609719bSwdenk
1396c609719bSwdenk	   Offset of environment data (variable area) to the
1397c609719bSwdenk	   beginning of flash memory; for instance, with bottom boot
1398c609719bSwdenk	   type flash chips the second sector can be used: the offset
1399c609719bSwdenk	   for this sector is given here.
1400c609719bSwdenk
1401c609719bSwdenk	   CFG_ENV_OFFSET is used relative to CFG_FLASH_BASE.
1402c609719bSwdenk
1403c609719bSwdenk	- CFG_ENV_ADDR:
1404c609719bSwdenk
1405c609719bSwdenk	   This is just another way to specify the start address of
1406c609719bSwdenk	   the flash sector containing the environment (instead of
1407c609719bSwdenk	   CFG_ENV_OFFSET).
1408c609719bSwdenk
1409c609719bSwdenk	- CFG_ENV_SECT_SIZE:
1410c609719bSwdenk
1411c609719bSwdenk	   Size of the sector containing the environment.
1412c609719bSwdenk
1413c609719bSwdenk
1414c609719bSwdenk	b) Sometimes flash chips have few, equal sized, BIG sectors.
1415c609719bSwdenk	   In such a case you don't want to spend a whole sector for
1416c609719bSwdenk	   the environment.
1417c609719bSwdenk
1418c609719bSwdenk	- CFG_ENV_SIZE:
1419c609719bSwdenk
1420c609719bSwdenk	   If you use this in combination with CFG_ENV_IS_IN_FLASH
1421c609719bSwdenk	   and CFG_ENV_SECT_SIZE, you can specify to use only a part
1422c609719bSwdenk	   of this flash sector for the environment. This saves
1423c609719bSwdenk	   memory for the RAM copy of the environment.
1424c609719bSwdenk
1425c609719bSwdenk	   It may also save flash memory if you decide to use this
1426c609719bSwdenk	   when your environment is "embedded" within U-Boot code,
1427c609719bSwdenk	   since then the remainder of the flash sector could be used
1428c609719bSwdenk	   for U-Boot code. It should be pointed out that this is
1429c609719bSwdenk	   STRONGLY DISCOURAGED from a robustness point of view:
1430c609719bSwdenk	   updating the environment in flash makes it always
1431c609719bSwdenk	   necessary to erase the WHOLE sector. If something goes
1432c609719bSwdenk	   wrong before the contents has been restored from a copy in
1433c609719bSwdenk	   RAM, your target system will be dead.
1434c609719bSwdenk
1435c609719bSwdenk	- CFG_ENV_ADDR_REDUND
1436c609719bSwdenk	  CFG_ENV_SIZE_REDUND
1437c609719bSwdenk
1438c609719bSwdenk	   These settings describe a second storage area used to hold
1439c609719bSwdenk	   a redundand copy of the environment data, so that there is
1440c609719bSwdenk	   a valid backup copy in case there is a power failur during
1441c609719bSwdenk	   a "saveenv" operation.
1442c609719bSwdenk
1443c609719bSwdenkBE CAREFUL! Any changes to the flash layout, and some changes to the
1444c609719bSwdenksource code will make it necessary to adapt <board>/u-boot.lds*
1445c609719bSwdenkaccordingly!
1446c609719bSwdenk
1447c609719bSwdenk
1448c609719bSwdenk- CFG_ENV_IS_IN_NVRAM:
1449c609719bSwdenk
1450c609719bSwdenk	Define this if you have some non-volatile memory device
1451c609719bSwdenk	(NVRAM, battery buffered SRAM) which you want to use for the
1452c609719bSwdenk	environment.
1453c609719bSwdenk
1454c609719bSwdenk	- CFG_ENV_ADDR:
1455c609719bSwdenk	- CFG_ENV_SIZE:
1456c609719bSwdenk
1457c609719bSwdenk	  These two #defines are used to determin the memory area you
1458c609719bSwdenk	  want to use for environment. It is assumed that this memory
1459c609719bSwdenk	  can just be read and written to, without any special
1460c609719bSwdenk	  provision.
1461c609719bSwdenk
1462c609719bSwdenkBE CAREFUL! The first access to the environment happens quite early
1463c609719bSwdenkin U-Boot initalization (when we try to get the setting of for the
1464c609719bSwdenkconsole baudrate). You *MUST* have mappend your NVRAM area then, or
1465c609719bSwdenkU-Boot will hang.
1466c609719bSwdenk
1467c609719bSwdenkPlease note that even with NVRAM we still use a copy of the
1468c609719bSwdenkenvironment in RAM: we could work on NVRAM directly, but we want to
1469c609719bSwdenkkeep settings there always unmodified except somebody uses "saveenv"
1470c609719bSwdenkto save the current settings.
1471c609719bSwdenk
1472c609719bSwdenk
1473c609719bSwdenk- CFG_ENV_IS_IN_EEPROM:
1474c609719bSwdenk
1475c609719bSwdenk	Use this if you have an EEPROM or similar serial access
1476c609719bSwdenk	device and a driver for it.
1477c609719bSwdenk
1478c609719bSwdenk	- CFG_ENV_OFFSET:
1479c609719bSwdenk	- CFG_ENV_SIZE:
1480c609719bSwdenk
1481c609719bSwdenk	  These two #defines specify the offset and size of the
1482c609719bSwdenk	  environment area within the total memory of your EEPROM.
1483c609719bSwdenk
1484c609719bSwdenk	- CFG_I2C_EEPROM_ADDR:
1485c609719bSwdenk	  If defined, specified the chip address of the EEPROM device.
1486c609719bSwdenk	  The default address is zero.
1487c609719bSwdenk
1488c609719bSwdenk	- CFG_EEPROM_PAGE_WRITE_BITS:
1489c609719bSwdenk	  If defined, the number of bits used to address bytes in a
1490c609719bSwdenk	  single page in the EEPROM device.  A 64 byte page, for example
1491c609719bSwdenk	  would require six bits.
1492c609719bSwdenk
1493c609719bSwdenk	- CFG_EEPROM_PAGE_WRITE_DELAY_MS:
1494c609719bSwdenk	  If defined, the number of milliseconds to delay between
1495c609719bSwdenk	  page writes.  The default is zero milliseconds.
1496c609719bSwdenk
1497c609719bSwdenk	- CFG_I2C_EEPROM_ADDR_LEN:
1498c609719bSwdenk	  The length in bytes of the EEPROM memory array address.  Note
1499c609719bSwdenk	  that this is NOT the chip address length!
1500c609719bSwdenk
1501c609719bSwdenk	- CFG_EEPROM_SIZE:
1502c609719bSwdenk	  The size in bytes of the EEPROM device.
1503c609719bSwdenk
1504c609719bSwdenk
1505c609719bSwdenk- CFG_SPI_INIT_OFFSET
1506c609719bSwdenk
1507c609719bSwdenk	Defines offset to the initial SPI buffer area in DPRAM. The
1508c609719bSwdenk	area is used at an early stage (ROM part) if the environment
1509c609719bSwdenk	is configured to reside in the SPI EEPROM: We need a 520 byte
1510c609719bSwdenk	scratch DPRAM area. It is used between the two initialization
1511c609719bSwdenk	calls (spi_init_f() and spi_init_r()). A value of 0xB00 seems
1512c609719bSwdenk	to be a good choice since it makes it far enough from the
1513c609719bSwdenk	start of the data area as well as from the stack pointer.
1514c609719bSwdenk
1515c609719bSwdenkPlease note that the environment is read-only as long as the monitor
1516c609719bSwdenkhas been relocated to RAM and a RAM copy of the environment has been
1517c609719bSwdenkcreated; also, when using EEPROM you will have to use getenv_r()
1518c609719bSwdenkuntil then to read environment variables.
1519c609719bSwdenk
1520c609719bSwdenkThe environment is now protected by a CRC32 checksum. Before the
1521c609719bSwdenkmonitor is relocated into RAM, as a result of a bad CRC you will be
1522c609719bSwdenkworking with the compiled-in default environment - *silently*!!!
1523c609719bSwdenk[This is necessary, because the first environment variable we need is
1524c609719bSwdenkthe "baudrate" setting for the console - if we have a bad CRC, we
1525c609719bSwdenkdon't have any device yet where we could complain.]
1526c609719bSwdenk
1527c609719bSwdenkNote: once the monitor has been relocated, then it will complain if
1528c609719bSwdenkthe default environment is used; a new CRC is computed as soon as you
1529c609719bSwdenkuse the "setenv" command to modify / delete / add any environment
1530c609719bSwdenkvariable [even when you try to delete a non-existing variable!].
1531c609719bSwdenk
1532c609719bSwdenkNote2: you must edit your u-boot.lds file to reflect this
1533c609719bSwdenkconfiguration.
1534c609719bSwdenk
1535c609719bSwdenk
1536c609719bSwdenkLow Level (hardware related) configuration options:
1537c609719bSwdenk
1538c609719bSwdenk- CFG_CACHELINE_SIZE:
1539c609719bSwdenk		Cache Line Size of the CPU.
1540c609719bSwdenk
1541c609719bSwdenk- CFG_DEFAULT_IMMR:
1542c609719bSwdenk		Default address of the IMMR after system reset.
1543c609719bSwdenk		Needed on some 8260 systems (MPC8260ADS and RPXsuper)
1544c609719bSwdenk		to be able to adjust the position of the IMMR
1545c609719bSwdenk		register after a reset.
1546c609719bSwdenk
15477f6c2cbcSwdenk- Floppy Disk Support:
15487f6c2cbcSwdenk		CFG_FDC_DRIVE_NUMBER
15497f6c2cbcSwdenk
15507f6c2cbcSwdenk		the default drive number (default value 0)
15517f6c2cbcSwdenk
15527f6c2cbcSwdenk		CFG_ISA_IO_STRIDE
15537f6c2cbcSwdenk
15547f6c2cbcSwdenk		defines the spacing between fdc chipset registers
15557f6c2cbcSwdenk		(default value 1)
15567f6c2cbcSwdenk
15577f6c2cbcSwdenk		CFG_ISA_IO_OFFSET
15587f6c2cbcSwdenk
15597f6c2cbcSwdenk		defines the offset of register from address. It
15607f6c2cbcSwdenk		depends on which part of the data bus is connected to
15617f6c2cbcSwdenk		the fdc chipset. (default value 0)
15627f6c2cbcSwdenk
15637f6c2cbcSwdenk		If CFG_ISA_IO_STRIDE CFG_ISA_IO_OFFSET and
15647f6c2cbcSwdenk		CFG_FDC_DRIVE_NUMBER are undefined, they take their
15657f6c2cbcSwdenk		default value.
15667f6c2cbcSwdenk
15677f6c2cbcSwdenk		if CFG_FDC_HW_INIT is defined, then the function
15687f6c2cbcSwdenk		fdc_hw_init() is called at the beginning of the FDC
15697f6c2cbcSwdenk		setup. fdc_hw_init() must be provided by the board
15707f6c2cbcSwdenk		source code. It is used to make hardware dependant
15717f6c2cbcSwdenk		initializations.
15727f6c2cbcSwdenk
1573c609719bSwdenk- CFG_IMMR:	Physical address of the Internal Memory Mapped
1574c609719bSwdenk		Register; DO NOT CHANGE! (11-4)
1575c609719bSwdenk		[MPC8xx systems only]
1576c609719bSwdenk
1577c609719bSwdenk- CFG_INIT_RAM_ADDR:
1578c609719bSwdenk
1579c609719bSwdenk		Start address of memory area tha can be used for
1580c609719bSwdenk		initial data and stack; please note that this must be
1581c609719bSwdenk		writable memory that is working WITHOUT special
1582c609719bSwdenk		initialization, i. e. you CANNOT use normal RAM which
1583c609719bSwdenk		will become available only after programming the
1584c609719bSwdenk		memory controller and running certain initialization
1585c609719bSwdenk		sequences.
1586c609719bSwdenk
1587c609719bSwdenk		U-Boot uses the following memory types:
1588c609719bSwdenk		- MPC8xx and MPC8260: IMMR (internal memory of the CPU)
1589c609719bSwdenk		- MPC824X: data cache
1590c609719bSwdenk		- PPC4xx:  data cache
1591c609719bSwdenk
1592c609719bSwdenk- CFG_INIT_DATA_OFFSET:
1593c609719bSwdenk
1594c609719bSwdenk		Offset of the initial data structure in the memory
1595c609719bSwdenk		area defined by CFG_INIT_RAM_ADDR. Usually
1596c609719bSwdenk		CFG_INIT_DATA_OFFSET is chosen such that the initial
1597c609719bSwdenk		data is located at the end of the available space
1598c609719bSwdenk		(sometimes written as (CFG_INIT_RAM_END -
1599c609719bSwdenk		CFG_INIT_DATA_SIZE), and the initial stack is just
1600c609719bSwdenk		below that area (growing from (CFG_INIT_RAM_ADDR +
1601c609719bSwdenk		CFG_INIT_DATA_OFFSET) downward.
1602c609719bSwdenk
1603c609719bSwdenk	Note:
1604c609719bSwdenk		On the MPC824X (or other systems that use the data
1605c609719bSwdenk		cache for initial memory) the address chosen for
1606c609719bSwdenk		CFG_INIT_RAM_ADDR is basically arbitrary - it must
1607c609719bSwdenk		point to an otherwise UNUSED address space between
1608c609719bSwdenk		the top of RAM and the start of the PCI space.
1609c609719bSwdenk
1610c609719bSwdenk- CFG_SIUMCR:	SIU Module Configuration (11-6)
1611c609719bSwdenk
1612c609719bSwdenk- CFG_SYPCR:	System Protection Control (11-9)
1613c609719bSwdenk
1614c609719bSwdenk- CFG_TBSCR:	Time Base Status and Control (11-26)
1615c609719bSwdenk
1616c609719bSwdenk- CFG_PISCR:	Periodic Interrupt Status and Control (11-31)
1617c609719bSwdenk
1618c609719bSwdenk- CFG_PLPRCR:	PLL, Low-Power, and Reset Control Register (15-30)
1619c609719bSwdenk
1620c609719bSwdenk- CFG_SCCR:	System Clock and reset Control Register (15-27)
1621c609719bSwdenk
1622c609719bSwdenk- CFG_OR_TIMING_SDRAM:
1623c609719bSwdenk		SDRAM timing
1624c609719bSwdenk
1625c609719bSwdenk- CFG_MAMR_PTA:
1626c609719bSwdenk		periodic timer for refresh
1627c609719bSwdenk
1628c609719bSwdenk- CFG_DER:	Debug Event Register (37-47)
1629c609719bSwdenk
1630c609719bSwdenk- FLASH_BASE0_PRELIM, FLASH_BASE1_PRELIM, CFG_REMAP_OR_AM,
1631c609719bSwdenk  CFG_PRELIM_OR_AM, CFG_OR_TIMING_FLASH, CFG_OR0_REMAP,
1632c609719bSwdenk  CFG_OR0_PRELIM, CFG_BR0_PRELIM, CFG_OR1_REMAP, CFG_OR1_PRELIM,
1633c609719bSwdenk  CFG_BR1_PRELIM:
1634c609719bSwdenk		Memory Controller Definitions: BR0/1 and OR0/1 (FLASH)
1635c609719bSwdenk
1636c609719bSwdenk- SDRAM_BASE2_PRELIM, SDRAM_BASE3_PRELIM, SDRAM_MAX_SIZE,
1637c609719bSwdenk  CFG_OR_TIMING_SDRAM, CFG_OR2_PRELIM, CFG_BR2_PRELIM,
1638c609719bSwdenk  CFG_OR3_PRELIM, CFG_BR3_PRELIM:
1639c609719bSwdenk		Memory Controller Definitions: BR2/3 and OR2/3 (SDRAM)
1640c609719bSwdenk
1641c609719bSwdenk- CFG_MAMR_PTA, CFG_MPTPR_2BK_4K, CFG_MPTPR_1BK_4K, CFG_MPTPR_2BK_8K,
1642c609719bSwdenk  CFG_MPTPR_1BK_8K, CFG_MAMR_8COL, CFG_MAMR_9COL:
1643c609719bSwdenk		Machine Mode Register and Memory Periodic Timer
1644c609719bSwdenk		Prescaler definitions (SDRAM timing)
1645c609719bSwdenk
1646c609719bSwdenk- CFG_I2C_UCODE_PATCH, CFG_I2C_DPMEM_OFFSET [0x1FC0]:
1647c609719bSwdenk		enable I2C microcode relocation patch (MPC8xx);
1648c609719bSwdenk		define relocation offset in DPRAM [DSP2]
1649c609719bSwdenk
1650c609719bSwdenk- CFG_SPI_UCODE_PATCH, CFG_SPI_DPMEM_OFFSET [0x1FC0]:
1651c609719bSwdenk		enable SPI microcode relocation patch (MPC8xx);
1652c609719bSwdenk		define relocation offset in DPRAM [SCC4]
1653c609719bSwdenk
1654c609719bSwdenk- CFG_USE_OSCCLK:
1655c609719bSwdenk		Use OSCM clock mode on MBX8xx board. Be careful,
1656c609719bSwdenk		wrong setting might damage your board. Read
1657c609719bSwdenk		doc/README.MBX before setting this variable!
1658c609719bSwdenk
1659ea909b76Swdenk- CFG_CPM_POST_WORD_ADDR: (MPC8xx, MPC8260 only)
1660ea909b76Swdenk		Offset of the bootmode word in DPRAM used by post
1661ea909b76Swdenk		(Power On Self Tests). This definition overrides
1662ea909b76Swdenk		#define'd default value in commproc.h resp.
1663ea909b76Swdenk		cpm_8260.h.
1664ea909b76Swdenk
1665c609719bSwdenkBuilding the Software:
1666c609719bSwdenk======================
1667c609719bSwdenk
1668c609719bSwdenkBuilding U-Boot has been tested in native PPC environments (on a
1669c609719bSwdenkPowerBook G3 running LinuxPPC 2000) and in cross environments
1670c609719bSwdenk(running RedHat 6.x and 7.x Linux on x86, Solaris 2.6 on a SPARC, and
1671c609719bSwdenkNetBSD 1.5 on x86).
1672c609719bSwdenk
1673c609719bSwdenkIf you are not using a native PPC environment, it is assumed that you
1674c609719bSwdenkhave the GNU cross compiling tools available in your path and named
1675c609719bSwdenkwith a prefix of "powerpc-linux-". If this is not the case, (e.g. if
1676c609719bSwdenkyou are using Monta Vista's Hard Hat Linux CDK 1.2) you must change
1677c609719bSwdenkthe definition of CROSS_COMPILE in Makefile. For HHL on a 4xx CPU,
1678c609719bSwdenkchange it to:
1679c609719bSwdenk
1680c609719bSwdenk	CROSS_COMPILE = ppc_4xx-
1681c609719bSwdenk
1682c609719bSwdenk
1683c609719bSwdenkU-Boot is intended to be  simple  to  build.  After  installing  the
1684c609719bSwdenksources	 you must configure U-Boot for one specific board type. This
1685c609719bSwdenkis done by typing:
1686c609719bSwdenk
1687c609719bSwdenk	make NAME_config
1688c609719bSwdenk
1689c609719bSwdenkwhere "NAME_config" is the name of one of the existing
1690c609719bSwdenkconfigurations; the following names are supported:
1691c609719bSwdenk
1692c609719bSwdenk    ADCIOP_config	  GTH_config		TQM850L_config
1693c609719bSwdenk    ADS860_config	  IP860_config		TQM855L_config
1694c609719bSwdenk    AR405_config	  IVML24_config		TQM860L_config
1695c609719bSwdenk    CANBT_config	  IVMS8_config		WALNUT405_config
1696c609719bSwdenk    CPCI405_config	  LANTEC_config		cogent_common_config
1697c609719bSwdenk    CPCIISER4_config	  MBX_config		cogent_mpc8260_config
1698c609719bSwdenk    CU824_config	  MBX860T_config	cogent_mpc8xx_config
1699c609719bSwdenk    ESTEEM192E_config	  RPXlite_config	hermes_config
1700c609719bSwdenk    ETX094_config	  RPXsuper_config	hymod_config
1701c609719bSwdenk    FADS823_config	  SM850_config		lwmon_config
1702c609719bSwdenk    FADS850SAR_config	  SPD823TS_config	pcu_e_config
1703c609719bSwdenk    FADS860T_config	  SXNI855T_config	rsdproto_config
1704c609719bSwdenk    FPS850L_config	  Sandpoint8240_config	sbc8260_config
1705c609719bSwdenk    GENIETV_config	  TQM823L_config	PIP405_config
1706384ae025Swdenk    GEN860T_config	  EBONY_config		FPS860L_config
1707c609719bSwdenk
1708c609719bSwdenkNote: for some board special configuration names may exist; check  if
1709c609719bSwdenk      additional  information is available from the board vendor; for
1710c609719bSwdenk      instance, the TQM8xxL systems run normally at 50 MHz and use  a
1711c609719bSwdenk      SCC  for	10baseT	 ethernet; there are also systems with 80 MHz
1712c609719bSwdenk      CPU clock, and an optional Fast Ethernet	module	is  available
1713c609719bSwdenk      for  CPU's  with FEC. You can select such additional "features"
1714c609719bSwdenk      when chosing the configuration, i. e.
1715c609719bSwdenk
1716c609719bSwdenk      make TQM860L_config
1717c609719bSwdenk	- will configure for a plain TQM860L, i. e. 50MHz, no FEC
1718c609719bSwdenk
1719c609719bSwdenk      make TQM860L_FEC_config
1720c609719bSwdenk	- will configure for a TQM860L at 50MHz with FEC for ethernet
1721c609719bSwdenk
1722c609719bSwdenk      make TQM860L_80MHz_config
1723c609719bSwdenk	- will configure for a TQM860L at 80 MHz, with normal 10baseT
1724c609719bSwdenk	  interface
1725c609719bSwdenk
1726c609719bSwdenk      make TQM860L_FEC_80MHz_config
1727c609719bSwdenk	- will configure for a TQM860L at 80 MHz with FEC for ethernet
1728c609719bSwdenk
1729c609719bSwdenk      make TQM823L_LCD_config
1730c609719bSwdenk	- will configure for a TQM823L with U-Boot console on LCD
1731c609719bSwdenk
1732c609719bSwdenk      make TQM823L_LCD_80MHz_config
1733c609719bSwdenk	- will configure for a TQM823L at 80 MHz with U-Boot console on LCD
1734c609719bSwdenk
1735c609719bSwdenk      etc.
1736c609719bSwdenk
1737c609719bSwdenk
1738c609719bSwdenk
1739c609719bSwdenkFinally, type "make all", and you should get some working U-Boot
1740c609719bSwdenkimages ready for downlod to / installation on your system:
1741c609719bSwdenk
1742c609719bSwdenk- "u-boot.bin" is a raw binary image
1743c609719bSwdenk- "u-boot" is an image in ELF binary format
1744c609719bSwdenk- "u-boot.srec" is in Motorola S-Record format
1745c609719bSwdenk
1746c609719bSwdenk
1747c609719bSwdenkPlease be aware that the Makefiles assume you are using GNU make, so
1748c609719bSwdenkfor instance on NetBSD you might need to use "gmake" instead of
1749c609719bSwdenknative "make".
1750c609719bSwdenk
1751c609719bSwdenk
1752c609719bSwdenkIf the system board that you have is not listed, then you will need
1753c609719bSwdenkto port U-Boot to your hardware platform. To do this, follow these
1754c609719bSwdenksteps:
1755c609719bSwdenk
1756c609719bSwdenk1.  Add a new configuration option for your board to the toplevel
1757c609719bSwdenk    "Makefile", using the existing entries as examples.
1758c609719bSwdenk2.  Create a new directory to hold your board specific code. Add any
1759c609719bSwdenk    files you need.
1760c609719bSwdenk3.  If you're porting U-Boot to a new CPU, then also create a new
1761c609719bSwdenk    directory to hold your CPU specific code. Add any files you need.
1762c609719bSwdenk4.  Run "make config_name" with your new name.
1763c609719bSwdenk5.  Type "make", and you should get a working "u-boot.srec" file
1764c609719bSwdenk    to be installed on your target system.
1765c609719bSwdenk    [Of course, this last step is much harder than it sounds.]
1766c609719bSwdenk
1767c609719bSwdenk
1768c609719bSwdenkTesting of U-Boot Modifications, Ports to New Hardware, etc.:
1769c609719bSwdenk==============================================================
1770c609719bSwdenk
1771c609719bSwdenkIf you have modified U-Boot sources (for instance added a new	board
1772c609719bSwdenkor  support  for  new  devices,	 a new CPU, etc.) you are expected to
1773c609719bSwdenkprovide feedback to the other developers. The feedback normally takes
1774c609719bSwdenkthe form of a "patch", i. e. a context diff against a certain (latest
1775c609719bSwdenkofficial or latest in CVS) version of U-Boot sources.
1776c609719bSwdenk
1777c609719bSwdenkBut before you submit such a patch, please verify that	your  modifi-
1778c609719bSwdenkcation	did not break existing code. At least make sure that *ALL* of
1779c609719bSwdenkthe supported boards compile WITHOUT ANY compiler warnings. To do so,
1780c609719bSwdenkjust run the "MAKEALL" script, which will configure and build U-Boot
1781c609719bSwdenkfor ALL supported system. Be warned, this will take a while. You  can
1782c609719bSwdenkselect	which  (cross)	compiler  to use py passing a `CROSS_COMPILE'
1783c609719bSwdenkenvironment variable to the script, i. e. to use the cross tools from
1784c609719bSwdenkMontaVista's Hard Hat Linux you can type
1785c609719bSwdenk
1786c609719bSwdenk	CROSS_COMPILE=ppc_8xx- MAKEALL
1787c609719bSwdenk
1788c609719bSwdenkor to build on a native PowerPC system you can type
1789c609719bSwdenk
1790c609719bSwdenk	CROSS_COMPILE=' ' MAKEALL
1791c609719bSwdenk
1792c609719bSwdenkSee also "U-Boot Porting Guide" below.
1793c609719bSwdenk
1794c609719bSwdenk
1795c609719bSwdenk
1796c609719bSwdenkMonitor Commands - Overview:
1797c609719bSwdenk============================
1798c609719bSwdenk
1799c609719bSwdenkgo	- start application at address 'addr'
1800c609719bSwdenkrun	- run commands in an environment variable
1801c609719bSwdenkbootm	- boot application image from memory
1802c609719bSwdenkbootp	- boot image via network using BootP/TFTP protocol
1803c609719bSwdenktftpboot- boot image via network using TFTP protocol
1804c609719bSwdenk	       and env variables "ipaddr" and "serverip"
1805c609719bSwdenk	       (and eventually "gatewayip")
1806c609719bSwdenkrarpboot- boot image via network using RARP/TFTP protocol
1807c609719bSwdenkdiskboot- boot from IDE devicebootd   - boot default, i.e., run 'bootcmd'
1808c609719bSwdenkloads	- load S-Record file over serial line
1809c609719bSwdenkloadb	- load binary file over serial line (kermit mode)
1810c609719bSwdenkmd	- memory display
1811c609719bSwdenkmm	- memory modify (auto-incrementing)
1812c609719bSwdenknm	- memory modify (constant address)
1813c609719bSwdenkmw	- memory write (fill)
1814c609719bSwdenkcp	- memory copy
1815c609719bSwdenkcmp	- memory compare
1816c609719bSwdenkcrc32	- checksum calculation
1817c609719bSwdenkimd     - i2c memory display
1818c609719bSwdenkimm     - i2c memory modify (auto-incrementing)
1819c609719bSwdenkinm     - i2c memory modify (constant address)
1820c609719bSwdenkimw     - i2c memory write (fill)
1821c609719bSwdenkicrc32  - i2c checksum calculation
1822c609719bSwdenkiprobe  - probe to discover valid I2C chip addresses
1823c609719bSwdenkiloop   - infinite loop on address range
1824c609719bSwdenkisdram  - print SDRAM configuration information
1825c609719bSwdenksspi    - SPI utility commands
1826c609719bSwdenkbase	- print or set address offset
1827c609719bSwdenkprintenv- print environment variables
1828c609719bSwdenksetenv	- set environment variables
1829c609719bSwdenksaveenv - save environment variables to persistent storage
1830c609719bSwdenkprotect - enable or disable FLASH write protection
1831c609719bSwdenkerase	- erase FLASH memory
1832c609719bSwdenkflinfo	- print FLASH memory information
1833c609719bSwdenkbdinfo	- print Board Info structure
1834c609719bSwdenkiminfo	- print header information for application image
1835c609719bSwdenkconinfo - print console devices and informations
1836c609719bSwdenkide	- IDE sub-system
1837c609719bSwdenkloop	- infinite loop on address range
1838c609719bSwdenkmtest	- simple RAM test
1839c609719bSwdenkicache	- enable or disable instruction cache
1840c609719bSwdenkdcache	- enable or disable data cache
1841c609719bSwdenkreset	- Perform RESET of the CPU
1842c609719bSwdenkecho	- echo args to console
1843c609719bSwdenkversion - print monitor version
1844c609719bSwdenkhelp	- print online help
1845c609719bSwdenk?	- alias for 'help'
1846c609719bSwdenk
1847c609719bSwdenk
1848c609719bSwdenkMonitor Commands - Detailed Description:
1849c609719bSwdenk========================================
1850c609719bSwdenk
1851c609719bSwdenkTODO.
1852c609719bSwdenk
1853c609719bSwdenkFor now: just type "help <command>".
1854c609719bSwdenk
1855c609719bSwdenk
1856c609719bSwdenkEnvironment Variables:
1857c609719bSwdenk======================
1858c609719bSwdenk
1859c609719bSwdenkU-Boot supports user configuration using Environment Variables which
1860c609719bSwdenkcan be made persistent by saving to Flash memory.
1861c609719bSwdenk
1862c609719bSwdenkEnvironment Variables are set using "setenv", printed using
1863c609719bSwdenk"printenv", and saved to Flash using "saveenv". Using "setenv"
1864c609719bSwdenkwithout a value can be used to delete a variable from the
1865c609719bSwdenkenvironment. As long as you don't save the environment you are
1866c609719bSwdenkworking with an in-memory copy. In case the Flash area containing the
1867c609719bSwdenkenvironment is erased by accident, a default environment is provided.
1868c609719bSwdenk
1869c609719bSwdenkSome configuration options can be set using Environment Variables:
1870c609719bSwdenk
1871c609719bSwdenk  baudrate	- see CONFIG_BAUDRATE
1872c609719bSwdenk
1873c609719bSwdenk  bootdelay	- see CONFIG_BOOTDELAY
1874c609719bSwdenk
1875c609719bSwdenk  bootcmd	- see CONFIG_BOOTCOMMAND
1876c609719bSwdenk
1877c609719bSwdenk  bootargs	- Boot arguments when booting an RTOS image
1878c609719bSwdenk
1879c609719bSwdenk  bootfile	- Name of the image to load with TFTP
1880c609719bSwdenk
1881c609719bSwdenk  autoload	- if set to "no" (any string beginning with 'n'),
1882c609719bSwdenk		  "bootp" will just load perform a lookup of the
1883c609719bSwdenk		  configuration from the BOOTP server, but not try to
1884c609719bSwdenk		  load any image using TFTP
1885c609719bSwdenk
1886c609719bSwdenk  autostart	- if set to "yes", an image loaded using the "bootp",
1887c609719bSwdenk		  "rarpboot", "tftpboot" or "diskboot" commands will
1888c609719bSwdenk		  be automatically started (by internally calling
1889c609719bSwdenk		  "bootm")
1890c609719bSwdenk
1891c609719bSwdenk  initrd_high	- restrict positioning of initrd images:
1892c609719bSwdenk		  If this variable is not set, initrd images will be
1893c609719bSwdenk		  copied to the highest possible address in RAM; this
1894c609719bSwdenk		  is usually what you want since it allows for
1895c609719bSwdenk		  maximum initrd size. If for some reason you want to
1896c609719bSwdenk		  make sure that the initrd image is loaded below the
1897c609719bSwdenk		  CFG_BOOTMAPSZ limit, you can set this environment
1898c609719bSwdenk		  variable to a value of "no" or "off" or "0".
1899c609719bSwdenk		  Alternatively, you can set it to a maximum upper
1900c609719bSwdenk		  address to use (U-Boot will still check that it
1901c609719bSwdenk		  does not overwrite the U-Boot stack and data).
1902c609719bSwdenk
1903c609719bSwdenk		  For instance, when you have a system with 16 MB
1904c609719bSwdenk		  RAM, and want to reseve 4 MB from use by Linux,
1905c609719bSwdenk		  you can do this by adding "mem=12M" to the value of
1906c609719bSwdenk		  the "bootargs" variable. However, now you must make
1907c609719bSwdenk		  sure, that the initrd image is placed in the first
1908c609719bSwdenk		  12 MB as well - this can be done with
1909c609719bSwdenk
1910c609719bSwdenk		  setenv initrd_high 00c00000
1911c609719bSwdenk
1912c609719bSwdenk  ipaddr	- IP address; needed for tftpboot command
1913c609719bSwdenk
1914c609719bSwdenk  loadaddr	- Default load address for commands like "bootp",
1915c609719bSwdenk		  "rarpboot", "tftpboot" or "diskboot"
1916c609719bSwdenk
1917c609719bSwdenk  loads_echo	- see CONFIG_LOADS_ECHO
1918c609719bSwdenk
1919c609719bSwdenk  serverip	- TFTP server IP address; needed for tftpboot command
1920c609719bSwdenk
1921c609719bSwdenk  bootretry	- see CONFIG_BOOT_RETRY_TIME
1922c609719bSwdenk
1923c609719bSwdenk  bootdelaykey	- see CONFIG_AUTOBOOT_DELAY_STR
1924c609719bSwdenk
1925c609719bSwdenk  bootstopkey	- see CONFIG_AUTOBOOT_STOP_STR
1926c609719bSwdenk
1927c609719bSwdenk
1928c609719bSwdenkThe following environment variables may be used and automatically
1929c609719bSwdenkupdated by the network boot commands ("bootp" and "rarpboot"),
1930c609719bSwdenkdepending the information provided by your boot server:
1931c609719bSwdenk
1932c609719bSwdenk  bootfile	- see above
1933c609719bSwdenk  dnsip		- IP address of your Domain Name Server
1934c609719bSwdenk  gatewayip	- IP address of the Gateway (Router) to use
1935c609719bSwdenk  hostname	- Target hostname
1936c609719bSwdenk  ipaddr	- see above
1937c609719bSwdenk  netmask	- Subnet Mask
1938c609719bSwdenk  rootpath	- Pathname of the root filesystem on the NFS server
1939c609719bSwdenk  serverip	- see above
1940c609719bSwdenk
1941c609719bSwdenk
1942c609719bSwdenkThere are two special Environment Variables:
1943c609719bSwdenk
1944c609719bSwdenk  serial#	- contains hardware identification information such
1945c609719bSwdenk		  as type string and/or serial number
1946c609719bSwdenk  ethaddr	- Ethernet address
1947c609719bSwdenk
1948c609719bSwdenkThese variables can be set only once (usually during manufacturing of
1949c609719bSwdenkthe board). U-Boot refuses to delete or overwrite these variables
1950c609719bSwdenkonce they have been set once.
1951c609719bSwdenk
1952c609719bSwdenk
1953c609719bSwdenkPlease note that changes to some configuration parameters may take
1954c609719bSwdenkonly effect after the next boot (yes, that's just like Windoze :-).
1955c609719bSwdenk
1956c609719bSwdenk
1957c609719bSwdenkNote for Redundant Ethernet Interfaces:
1958c609719bSwdenk=======================================
1959c609719bSwdenk
1960c609719bSwdenkSome boards come with redundand ethernet interfaces; U-Boot supports
1961c609719bSwdenksuch configurations and is capable of automatic selection of a
1962c609719bSwdenk"working" interface when needed. MAC assignemnt works as follows:
1963c609719bSwdenk
1964c609719bSwdenkNetwork interfaces are numbered eth0, eth1, eth2, ... Corresponding
1965c609719bSwdenkMAC addresses can be stored in the environment as "ethaddr" (=>eth0),
1966c609719bSwdenk"eth1addr" (=>eth1), "eth2addr", ...
1967c609719bSwdenk
1968c609719bSwdenkIf the network interface stores some valid MAC address (for instance
1969c609719bSwdenkin SROM), this is used as default address if there is NO correspon-
1970c609719bSwdenkding setting in the environment; if the corresponding environment
1971c609719bSwdenkvariable is set, this overrides the settings in the card; that means:
1972c609719bSwdenk
1973c609719bSwdenko If the SROM has a valid MAC address, and there is no address in the
1974c609719bSwdenk  environment, the SROM's address is used.
1975c609719bSwdenk
1976c609719bSwdenko If there is no valid address in the SROM, and a definition in the
1977c609719bSwdenk  environment exists, then the value from the environment variable is
1978c609719bSwdenk  used.
1979c609719bSwdenk
1980c609719bSwdenko If both the SROM and the environment contain a MAC address, and
1981c609719bSwdenk  both addresses are the same, this MAC address is used.
1982c609719bSwdenk
1983c609719bSwdenko If both the SROM and the environment contain a MAC address, and the
1984c609719bSwdenk  addresses differ, the value from the environment is used and a
1985c609719bSwdenk  warning is printed.
1986c609719bSwdenk
1987c609719bSwdenko If neither SROM nor the environment contain a MAC address, an error
1988c609719bSwdenk  is raised.
1989c609719bSwdenk
1990c609719bSwdenk
1991c609719bSwdenk
1992c609719bSwdenkImage Formats:
1993c609719bSwdenk==============
1994c609719bSwdenk
1995c609719bSwdenkThe "boot" commands of this monitor operate on "image" files which
1996c609719bSwdenkcan be basicly anything, preceeded by a special header; see the
1997c609719bSwdenkdefinitions in include/image.h for details; basicly, the header
1998c609719bSwdenkdefines the following image properties:
1999c609719bSwdenk
2000c609719bSwdenk* Target Operating System (Provisions for OpenBSD, NetBSD, FreeBSD,
2001c609719bSwdenk  4.4BSD, Linux, SVR4, Esix, Solaris, Irix, SCO, Dell, NCR, VxWorks,
2002c609719bSwdenk  LynxOS, pSOS, QNX;
2003c609719bSwdenk  Currently supported: Linux, NetBSD, VxWorks, QNX).
2004c609719bSwdenk* Target CPU Architecture (Provisions for Alpha, ARM, Intel x86,
2005c609719bSwdenk  IA64, MIPS, MIPS, PowerPC, IBM S390, SuperH, Sparc, Sparc 64 Bit;
2006c609719bSwdenk  Currently supported: PowerPC).
2007c609719bSwdenk* Compression Type (Provisions for uncompressed, gzip, bzip2;
2008c609719bSwdenk  Currently supported: uncompressed, gzip).
2009c609719bSwdenk* Load Address
2010c609719bSwdenk* Entry Point
2011c609719bSwdenk* Image Name
2012c609719bSwdenk* Image Timestamp
2013c609719bSwdenk
2014c609719bSwdenkThe header is marked by a special Magic Number, and both the header
2015c609719bSwdenkand the data portions of the image are secured against corruption by
2016c609719bSwdenkCRC32 checksums.
2017c609719bSwdenk
2018c609719bSwdenk
2019c609719bSwdenkLinux Support:
2020c609719bSwdenk==============
2021c609719bSwdenk
2022c609719bSwdenkAlthough U-Boot should support any OS or standalone application
2023c609719bSwdenkeasily, Linux has always been in the focus during the design of
2024c609719bSwdenkU-Boot.
2025c609719bSwdenk
2026c609719bSwdenkU-Boot includes many features that so far have been part of some
2027c609719bSwdenkspecial "boot loader" code within the Linux kernel. Also, any
2028c609719bSwdenk"initrd" images to be used are no longer part of one big Linux image;
2029c609719bSwdenkinstead, kernel and "initrd" are separate images. This implementation
2030c609719bSwdenkserves serveral purposes:
2031c609719bSwdenk
2032c609719bSwdenk- the same features can be used for other OS or standalone
2033c609719bSwdenk  applications (for instance: using compressed images to reduce the
2034c609719bSwdenk  Flash memory footprint)
2035c609719bSwdenk
2036c609719bSwdenk- it becomes much easier to port new Linux kernel versions because
2037c609719bSwdenk  lots of low-level, hardware dependend stuff are done by U-Boot
2038c609719bSwdenk
2039c609719bSwdenk- the same Linux kernel image can now be used with different "initrd"
2040c609719bSwdenk  images; of course this also means that different kernel images can
2041c609719bSwdenk  be run with the same "initrd". This makes testing easier (you don't
2042c609719bSwdenk  have to build a new "zImage.initrd" Linux image when you just
2043c609719bSwdenk  change a file in your "initrd"). Also, a field-upgrade of the
2044c609719bSwdenk  software is easier now.
2045c609719bSwdenk
2046c609719bSwdenk
2047c609719bSwdenkLinux HOWTO:
2048c609719bSwdenk============
2049c609719bSwdenk
2050c609719bSwdenkPorting Linux to U-Boot based systems:
2051c609719bSwdenk---------------------------------------
2052c609719bSwdenk
2053c609719bSwdenkU-Boot cannot save you from doing all the necessary modifications to
2054c609719bSwdenkconfigure the Linux device drivers for use with your target hardware
2055c609719bSwdenk(no, we don't intend to provide a full virtual machine interface to
2056c609719bSwdenkLinux :-).
2057c609719bSwdenk
2058c609719bSwdenkBut now you can ignore ALL boot loader code (in arch/ppc/mbxboot).
2059c609719bSwdenk
2060c609719bSwdenkJust make sure your machine specific header file (for instance
2061c609719bSwdenkinclude/asm-ppc/tqm8xx.h) includes the same definition of the Board
2062c609719bSwdenkInformation structure as we define in include/u-boot.h, and make
2063c609719bSwdenksure that your definition of IMAP_ADDR uses the same value as your
2064c609719bSwdenkU-Boot configuration in CFG_IMMR.
2065c609719bSwdenk
2066c609719bSwdenk
2067c609719bSwdenkConfiguring the Linux kernel:
2068c609719bSwdenk-----------------------------
2069c609719bSwdenk
2070c609719bSwdenkNo specific requirements for U-Boot. Make sure you have some root
2071c609719bSwdenkdevice (initial ramdisk, NFS) for your target system.
2072c609719bSwdenk
2073c609719bSwdenk
2074c609719bSwdenkBuilding a Linux Image:
2075c609719bSwdenk-----------------------
2076c609719bSwdenk
207724ee89b9SwdenkWith U-Boot, "normal" build targets like "zImage" or "bzImage" are
207824ee89b9Swdenknot used. If you use recent kernel source, a new build target
207924ee89b9Swdenk"uImage" will exist which automatically builds an image usable by
208024ee89b9SwdenkU-Boot. Most older kernels also have support for a "pImage" target,
208124ee89b9Swdenkwhich was introduced for our predecessor project PPCBoot and uses a
208224ee89b9Swdenk100% compatible format.
2083c609719bSwdenk
2084c609719bSwdenkExample:
2085c609719bSwdenk
2086c609719bSwdenk	make TQM850L_config
2087c609719bSwdenk	make oldconfig
2088c609719bSwdenk	make dep
208924ee89b9Swdenk	make uImage
2090c609719bSwdenk
209124ee89b9SwdenkThe "uImage" build target uses a special tool (in 'tools/mkimage') to
209224ee89b9Swdenkencapsulate a compressed Linux kernel image with header  information,
209324ee89b9SwdenkCRC32 checksum etc. for use with U-Boot. This is what we are doing:
2094c609719bSwdenk
209524ee89b9Swdenk* build a standard "vmlinux" kernel image (in ELF binary format):
209624ee89b9Swdenk
209724ee89b9Swdenk* convert the kernel into a raw binary image:
209824ee89b9Swdenk
209924ee89b9Swdenk	${CROSS_COMPILE}-objcopy -O binary \
210024ee89b9Swdenk				 -R .note -R .comment \
210124ee89b9Swdenk				 -S vmlinux linux.bin
210224ee89b9Swdenk
210324ee89b9Swdenk* compress the binary image:
210424ee89b9Swdenk
210524ee89b9Swdenk	gzip -9 linux.bin
210624ee89b9Swdenk
210724ee89b9Swdenk* package compressed binary image for U-Boot:
210824ee89b9Swdenk
210924ee89b9Swdenk	mkimage -A ppc -O linux -T kernel -C gzip \
211024ee89b9Swdenk		-a 0 -e 0 -n "Linux Kernel Image" \
211124ee89b9Swdenk		-d linux.bin.gz uImage
211224ee89b9Swdenk
211324ee89b9Swdenk
211424ee89b9SwdenkThe "mkimage" tool can also be used to create ramdisk images for use
211524ee89b9Swdenkwith U-Boot, either separated from the Linux kernel image, or
211624ee89b9Swdenkcombined into one file. "mkimage" encapsulates the images with a 64
211724ee89b9Swdenkbyte header containing information about target architecture,
211824ee89b9Swdenkoperating system, image type, compression method, entry points, time
211924ee89b9Swdenkstamp, CRC32 checksums, etc.
212024ee89b9Swdenk
212124ee89b9Swdenk"mkimage" can be called in two ways: to verify existing images and
212224ee89b9Swdenkprint the header information, or to build new images.
2123c609719bSwdenk
2124c609719bSwdenkIn the first form (with "-l" option) mkimage lists the information
2125c609719bSwdenkcontained in the header of an existing U-Boot image; this includes
2126c609719bSwdenkchecksum verification:
2127c609719bSwdenk
2128c609719bSwdenk	tools/mkimage -l image
2129c609719bSwdenk	  -l ==> list image header information
2130c609719bSwdenk
2131c609719bSwdenkThe second form (with "-d" option) is used to build a U-Boot image
2132c609719bSwdenkfrom a "data file" which is used as image payload:
2133c609719bSwdenk
2134c609719bSwdenk	tools/mkimage -A arch -O os -T type -C comp -a addr -e ep \
2135c609719bSwdenk		      -n name -d data_file image
2136c609719bSwdenk	  -A ==> set architecture to 'arch'
2137c609719bSwdenk	  -O ==> set operating system to 'os'
2138c609719bSwdenk	  -T ==> set image type to 'type'
2139c609719bSwdenk	  -C ==> set compression type 'comp'
2140c609719bSwdenk	  -a ==> set load address to 'addr' (hex)
2141c609719bSwdenk	  -e ==> set entry point to 'ep' (hex)
2142c609719bSwdenk	  -n ==> set image name to 'name'
2143c609719bSwdenk	  -d ==> use image data from 'datafile'
2144c609719bSwdenk
2145c609719bSwdenkRight now, all Linux kernels use the same load address	(0x00000000),
2146c609719bSwdenkbut the entry point address depends on the kernel version:
2147c609719bSwdenk
2148c609719bSwdenk- 2.2.x kernels have the entry point at 0x0000000C,
214924ee89b9Swdenk- 2.3.x and later kernels have the entry point at 0x00000000.
2150c609719bSwdenk
2151c609719bSwdenkSo a typical call to build a U-Boot image would read:
2152c609719bSwdenk
215324ee89b9Swdenk	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
215424ee89b9Swdenk	> -A ppc -O linux -T kernel -C gzip -a 0 -e 0 \
215524ee89b9Swdenk	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz \
215624ee89b9Swdenk	> examples/uImage.TQM850L
215724ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2158c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2159c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2160c609719bSwdenk	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2161c609719bSwdenk	Load Address: 0x00000000
216224ee89b9Swdenk	Entry Point:  0x00000000
2163c609719bSwdenk
2164c609719bSwdenkTo verify the contents of the image (or check for corruption):
2165c609719bSwdenk
216624ee89b9Swdenk	-> tools/mkimage -l examples/uImage.TQM850L
216724ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2168c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2169c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (gzip compressed)
2170c609719bSwdenk	Data Size:    335725 Bytes = 327.86 kB = 0.32 MB
2171c609719bSwdenk	Load Address: 0x00000000
217224ee89b9Swdenk	Entry Point:  0x00000000
2173c609719bSwdenk
2174c609719bSwdenkNOTE: for embedded systems where boot time is critical you can trade
2175c609719bSwdenkspeed for memory and install an UNCOMPRESSED image instead: this
2176c609719bSwdenkneeds more space in Flash, but boots much faster since it does not
2177c609719bSwdenkneed to be uncompressed:
2178c609719bSwdenk
217924ee89b9Swdenk	-> gunzip /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux.gz
218024ee89b9Swdenk	-> tools/mkimage -n '2.4.4 kernel for TQM850L' \
218124ee89b9Swdenk	> -A ppc -O linux -T kernel -C none -a 0 -e 0 \
218224ee89b9Swdenk	> -d /opt/elsk/ppc_8xx/usr/src/linux-2.4.4/arch/ppc/coffboot/vmlinux \
218324ee89b9Swdenk	> examples/uImage.TQM850L-uncompressed
218424ee89b9Swdenk	Image Name:   2.4.4 kernel for TQM850L
2185c609719bSwdenk	Created:      Wed Jul 19 02:34:59 2000
2186c609719bSwdenk	Image Type:   PowerPC Linux Kernel Image (uncompressed)
2187c609719bSwdenk	Data Size:    792160 Bytes = 773.59 kB = 0.76 MB
2188c609719bSwdenk	Load Address: 0x00000000
218924ee89b9Swdenk	Entry Point:  0x00000000
2190c609719bSwdenk
2191c609719bSwdenk
2192c609719bSwdenkSimilar you can build U-Boot images from a 'ramdisk.image.gz' file
2193c609719bSwdenkwhen your kernel is intended to use an initial ramdisk:
2194c609719bSwdenk
2195c609719bSwdenk	-> tools/mkimage -n 'Simple Ramdisk Image' \
2196c609719bSwdenk	> -A ppc -O linux -T ramdisk -C gzip \
2197c609719bSwdenk	> -d /LinuxPPC/images/SIMPLE-ramdisk.image.gz examples/simple-initrd
2198c609719bSwdenk	Image Name:   Simple Ramdisk Image
2199c609719bSwdenk	Created:      Wed Jan 12 14:01:50 2000
2200c609719bSwdenk	Image Type:   PowerPC Linux RAMDisk Image (gzip compressed)
2201c609719bSwdenk	Data Size:    566530 Bytes = 553.25 kB = 0.54 MB
2202c609719bSwdenk	Load Address: 0x00000000
2203c609719bSwdenk	Entry Point:  0x00000000
2204c609719bSwdenk
2205c609719bSwdenk
2206c609719bSwdenkInstalling a Linux Image:
2207c609719bSwdenk-------------------------
2208c609719bSwdenk
2209c609719bSwdenkTo downloading a U-Boot image over the serial (console) interface,
2210c609719bSwdenkyou must convert the image to S-Record format:
2211c609719bSwdenk
2212c609719bSwdenk	objcopy -I binary -O srec examples/image examples/image.srec
2213c609719bSwdenk
2214c609719bSwdenkThe 'objcopy' does not understand the information in the U-Boot
2215c609719bSwdenkimage header, so the resulting S-Record file will be relative to
2216c609719bSwdenkaddress 0x00000000. To load it to a given address, you need to
2217c609719bSwdenkspecify the target address as 'offset' parameter with the 'loads'
2218c609719bSwdenkcommand.
2219c609719bSwdenk
2220c609719bSwdenkExample: install the image to address 0x40100000 (which on the
2221c609719bSwdenkTQM8xxL is in the first Flash bank):
2222c609719bSwdenk
2223c609719bSwdenk	=> erase 40100000 401FFFFF
2224c609719bSwdenk
2225c609719bSwdenk	.......... done
2226c609719bSwdenk	Erased 8 sectors
2227c609719bSwdenk
2228c609719bSwdenk	=> loads 40100000
2229c609719bSwdenk	## Ready for S-Record download ...
2230c609719bSwdenk	~>examples/image.srec
2231c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 12 13 ...
2232c609719bSwdenk	...
2233c609719bSwdenk	15989 15990 15991 15992
2234c609719bSwdenk	[file transfer complete]
2235c609719bSwdenk	[connected]
2236c609719bSwdenk	## Start Addr = 0x00000000
2237c609719bSwdenk
2238c609719bSwdenk
2239c609719bSwdenkYou can check the success of the download using the 'iminfo' command;
2240c609719bSwdenkthis includes a checksum verification so you  can  be  sure  no	 data
2241c609719bSwdenkcorruption happened:
2242c609719bSwdenk
2243c609719bSwdenk	=> imi 40100000
2244c609719bSwdenk
2245c609719bSwdenk	## Checking Image at 40100000 ...
2246c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2247c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2248c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2249c609719bSwdenk	   Load Address: 00000000
2250c609719bSwdenk	   Entry Point:	 0000000c
2251c609719bSwdenk	   Verifying Checksum ... OK
2252c609719bSwdenk
2253c609719bSwdenk
2254c609719bSwdenk
2255c609719bSwdenkBoot Linux:
2256c609719bSwdenk-----------
2257c609719bSwdenk
2258c609719bSwdenkThe "bootm" command is used to boot an application that is stored in
2259c609719bSwdenkmemory (RAM or Flash). In case of a Linux kernel image, the contents
2260c609719bSwdenkof the "bootargs" environment variable is passed to the kernel as
2261c609719bSwdenkparameters. You can check and modify this variable using the
2262c609719bSwdenk"printenv" and "setenv" commands:
2263c609719bSwdenk
2264c609719bSwdenk
2265c609719bSwdenk	=> printenv bootargs
2266c609719bSwdenk	bootargs=root=/dev/ram
2267c609719bSwdenk
2268c609719bSwdenk	=> setenv bootargs root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2269c609719bSwdenk
2270c609719bSwdenk	=> printenv bootargs
2271c609719bSwdenk	bootargs=root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2272c609719bSwdenk
2273c609719bSwdenk	=> bootm 40020000
2274c609719bSwdenk	## Booting Linux kernel at 40020000 ...
2275c609719bSwdenk	   Image Name:	 2.2.13 for NFS on TQM850L
2276c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2277c609719bSwdenk	   Data Size:	 381681 Bytes = 372 kB = 0 MB
2278c609719bSwdenk	   Load Address: 00000000
2279c609719bSwdenk	   Entry Point:	 0000000c
2280c609719bSwdenk	   Verifying Checksum ... OK
2281c609719bSwdenk	   Uncompressing Kernel Image ... OK
2282c609719bSwdenk	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
2283c609719bSwdenk	Boot arguments: root=/dev/nfs rw nfsroot=10.0.0.2:/LinuxPPC nfsaddrs=10.0.0.99:10.0.0.2
2284c609719bSwdenk	time_init: decrementer frequency = 187500000/60
2285c609719bSwdenk	Calibrating delay loop... 49.77 BogoMIPS
2286c609719bSwdenk	Memory: 15208k available (700k kernel code, 444k data, 32k init) [c0000000,c1000000]
2287c609719bSwdenk	...
2288c609719bSwdenk
2289c609719bSwdenkIf you want to boot a Linux kernel with initial ram disk, you pass
2290c609719bSwdenkthe memory addreses of both the kernel and the initrd image (PPBCOOT
2291c609719bSwdenkformat!) to the "bootm" command:
2292c609719bSwdenk
2293c609719bSwdenk	=> imi 40100000 40200000
2294c609719bSwdenk
2295c609719bSwdenk	## Checking Image at 40100000 ...
2296c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2297c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2298c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2299c609719bSwdenk	   Load Address: 00000000
2300c609719bSwdenk	   Entry Point:	 0000000c
2301c609719bSwdenk	   Verifying Checksum ... OK
2302c609719bSwdenk
2303c609719bSwdenk	## Checking Image at 40200000 ...
2304c609719bSwdenk	   Image Name:	 Simple Ramdisk Image
2305c609719bSwdenk	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2306c609719bSwdenk	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2307c609719bSwdenk	   Load Address: 00000000
2308c609719bSwdenk	   Entry Point:	 00000000
2309c609719bSwdenk	   Verifying Checksum ... OK
2310c609719bSwdenk
2311c609719bSwdenk	=> bootm 40100000 40200000
2312c609719bSwdenk	## Booting Linux kernel at 40100000 ...
2313c609719bSwdenk	   Image Name:	 2.2.13 for initrd on TQM850L
2314c609719bSwdenk	   Image Type:	 PowerPC Linux Kernel Image (gzip compressed)
2315c609719bSwdenk	   Data Size:	 335725 Bytes = 327 kB = 0 MB
2316c609719bSwdenk	   Load Address: 00000000
2317c609719bSwdenk	   Entry Point:	 0000000c
2318c609719bSwdenk	   Verifying Checksum ... OK
2319c609719bSwdenk	   Uncompressing Kernel Image ... OK
2320c609719bSwdenk	## Loading RAMDisk Image at 40200000 ...
2321c609719bSwdenk	   Image Name:	 Simple Ramdisk Image
2322c609719bSwdenk	   Image Type:	 PowerPC Linux RAMDisk Image (gzip compressed)
2323c609719bSwdenk	   Data Size:	 566530 Bytes = 553 kB = 0 MB
2324c609719bSwdenk	   Load Address: 00000000
2325c609719bSwdenk	   Entry Point:	 00000000
2326c609719bSwdenk	   Verifying Checksum ... OK
2327c609719bSwdenk	   Loading Ramdisk ... OK
2328c609719bSwdenk	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
2329c609719bSwdenk	Boot arguments: root=/dev/ram
2330c609719bSwdenk	time_init: decrementer frequency = 187500000/60
2331c609719bSwdenk	Calibrating delay loop... 49.77 BogoMIPS
2332c609719bSwdenk	...
2333c609719bSwdenk	RAMDISK: Compressed image found at block 0
2334c609719bSwdenk	VFS: Mounted root (ext2 filesystem).
2335c609719bSwdenk
2336c609719bSwdenk	bash#
2337c609719bSwdenk
23386069ff26SwdenkMore About U-Boot Image Types:
23396069ff26Swdenk------------------------------
23406069ff26Swdenk
23416069ff26SwdenkU-Boot supports the following image types:
23426069ff26Swdenk
23436069ff26Swdenk   "Standalone Programs" are directly runnable in the environment
23446069ff26Swdenk  	provided by U-Boot; it is expected that (if they behave
23456069ff26Swdenk  	well) you can continue to work in U-Boot after return from
23466069ff26Swdenk  	the Standalone Program.
23476069ff26Swdenk   "OS Kernel Images" are usually images of some Embedded OS which
23486069ff26Swdenk  	will take over control completely. Usually these programs
23496069ff26Swdenk  	will install their own set of exception handlers, device
23506069ff26Swdenk  	drivers, set up the MMU, etc. - this means, that you cannot
23516069ff26Swdenk  	expect to re-enter U-Boot except by resetting the CPU.
23526069ff26Swdenk   "RAMDisk Images" are more or less just data blocks, and their
23536069ff26Swdenk  	parameters (address, size) are passed to an OS kernel that is
23546069ff26Swdenk  	being started.
23556069ff26Swdenk   "Multi-File Images" contain several images, typically an OS
23566069ff26Swdenk  	(Linux) kernel image and one or more data images like
23576069ff26Swdenk  	RAMDisks. This construct is useful for instance when you want
23586069ff26Swdenk  	to boot over the network using BOOTP etc., where the boot
23596069ff26Swdenk  	server provides just a single image file, but you want to get
23606069ff26Swdenk  	for instance an OS kernel and a RAMDisk image.
23616069ff26Swdenk
23626069ff26Swdenk  	"Multi-File Images" start with a list of image sizes, each
23636069ff26Swdenk  	image size (in bytes) specified by an "uint32_t" in network
23646069ff26Swdenk  	byte order. This list is terminated by an "(uint32_t)0".
23656069ff26Swdenk  	Immediately after the terminating 0 follow the images, one by
23666069ff26Swdenk  	one, all aligned on "uint32_t" boundaries (size rounded up to
23676069ff26Swdenk  	a multiple of 4 bytes).
23686069ff26Swdenk
23696069ff26Swdenk   "Firmware Images" are binary images containing firmware (like
23706069ff26Swdenk  	U-Boot or FPGA images) which usually will be programmed to
23716069ff26Swdenk  	flash memory.
23726069ff26Swdenk
23736069ff26Swdenk   "Script files" are command sequences that will be executed by
23746069ff26Swdenk  	U-Boot's command interpreter; this feature is especially
23756069ff26Swdenk  	useful when you configure U-Boot to use a real shell (hush)
23766069ff26Swdenk  	as command interpreter.
23776069ff26Swdenk
2378c609719bSwdenk
2379c609719bSwdenkStandalone HOWTO:
2380c609719bSwdenk=================
2381c609719bSwdenk
2382c609719bSwdenkOne of the features of U-Boot is that you can dynamically load and
2383c609719bSwdenkrun "standalone" applications, which can use some resources of
2384c609719bSwdenkU-Boot like console I/O functions or interrupt services.
2385c609719bSwdenk
2386c609719bSwdenkTwo simple examples are included with the sources:
2387c609719bSwdenk
2388c609719bSwdenk"Hello World" Demo:
2389c609719bSwdenk-------------------
2390c609719bSwdenk
2391c609719bSwdenk'examples/hello_world.c' contains a small "Hello World" Demo
2392c609719bSwdenkapplication; it is automatically compiled when you build U-Boot.
2393c609719bSwdenkIt's configured to run at address 0x00040004, so you can play with it
2394c609719bSwdenklike that:
2395c609719bSwdenk
2396c609719bSwdenk	=> loads
2397c609719bSwdenk	## Ready for S-Record download ...
2398c609719bSwdenk	~>examples/hello_world.srec
2399c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 ...
2400c609719bSwdenk	[file transfer complete]
2401c609719bSwdenk	[connected]
2402c609719bSwdenk	## Start Addr = 0x00040004
2403c609719bSwdenk
2404c609719bSwdenk	=> go 40004 Hello World! This is a test.
2405c609719bSwdenk	## Starting application at 0x00040004 ...
2406c609719bSwdenk	Hello World
2407c609719bSwdenk	argc = 7
2408c609719bSwdenk	argv[0] = "40004"
2409c609719bSwdenk	argv[1] = "Hello"
2410c609719bSwdenk	argv[2] = "World!"
2411c609719bSwdenk	argv[3] = "This"
2412c609719bSwdenk	argv[4] = "is"
2413c609719bSwdenk	argv[5] = "a"
2414c609719bSwdenk	argv[6] = "test."
2415c609719bSwdenk	argv[7] = "<NULL>"
2416c609719bSwdenk	Hit any key to exit ...
2417c609719bSwdenk
2418c609719bSwdenk	## Application terminated, rc = 0x0
2419c609719bSwdenk
2420c609719bSwdenkAnother example, which demonstrates how to register a CPM interrupt
2421c609719bSwdenkhandler with the U-Boot code, can be found in 'examples/timer.c'.
2422c609719bSwdenkHere, a CPM timer is set up to generate an interrupt every second.
2423c609719bSwdenkThe interrupt service routine is trivial, just printing a '.'
2424c609719bSwdenkcharacter, but this is just a demo program. The application can be
2425c609719bSwdenkcontrolled by the following keys:
2426c609719bSwdenk
2427c609719bSwdenk	? - print current values og the CPM Timer registers
2428c609719bSwdenk	b - enable interrupts and start timer
2429c609719bSwdenk	e - stop timer and disable interrupts
2430c609719bSwdenk	q - quit application
2431c609719bSwdenk
2432c609719bSwdenk	=> loads
2433c609719bSwdenk	## Ready for S-Record download ...
2434c609719bSwdenk	~>examples/timer.srec
2435c609719bSwdenk	1 2 3 4 5 6 7 8 9 10 11 ...
2436c609719bSwdenk	[file transfer complete]
2437c609719bSwdenk	[connected]
2438c609719bSwdenk	## Start Addr = 0x00040004
2439c609719bSwdenk
2440c609719bSwdenk	=> go 40004
2441c609719bSwdenk	## Starting application at 0x00040004 ...
2442c609719bSwdenk	TIMERS=0xfff00980
2443c609719bSwdenk	Using timer 1
2444c609719bSwdenk	  tgcr @ 0xfff00980, tmr @ 0xfff00990, trr @ 0xfff00994, tcr @ 0xfff00998, tcn @ 0xfff0099c, ter @ 0xfff009b0
2445c609719bSwdenk
2446c609719bSwdenkHit 'b':
2447c609719bSwdenk	[q, b, e, ?] Set interval 1000000 us
2448c609719bSwdenk	Enabling timer
2449c609719bSwdenkHit '?':
2450c609719bSwdenk	[q, b, e, ?] ........
2451c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0xef6, ter=0x0
2452c609719bSwdenkHit '?':
2453c609719bSwdenk	[q, b, e, ?] .
2454c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x2ad4, ter=0x0
2455c609719bSwdenkHit '?':
2456c609719bSwdenk	[q, b, e, ?] .
2457c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x1efc, ter=0x0
2458c609719bSwdenkHit '?':
2459c609719bSwdenk	[q, b, e, ?] .
2460c609719bSwdenk	tgcr=0x1, tmr=0xff1c, trr=0x3d09, tcr=0x0, tcn=0x169d, ter=0x0
2461c609719bSwdenkHit 'e':
2462c609719bSwdenk	[q, b, e, ?] ...Stopping timer
2463c609719bSwdenkHit 'q':
2464c609719bSwdenk	[q, b, e, ?] ## Application terminated, rc = 0x0
2465c609719bSwdenk
2466c609719bSwdenk
2467c609719bSwdenkNetBSD Notes:
2468c609719bSwdenk=============
2469c609719bSwdenk
2470c609719bSwdenkStarting at version 0.9.2, U-Boot supports NetBSD both as host
2471c609719bSwdenk(build U-Boot) and target system (boots NetBSD/mpc8xx).
2472c609719bSwdenk
2473c609719bSwdenkBuilding requires a cross environment; it is known to work on
2474c609719bSwdenkNetBSD/i386 with the cross-powerpc-netbsd-1.3 package (you will also
2475c609719bSwdenkneed gmake since the Makefiles are not compatible with BSD make).
2476c609719bSwdenkNote that the cross-powerpc package does not install include files;
2477c609719bSwdenkattempting to build U-Boot will fail because <machine/ansi.h> is
2478c609719bSwdenkmissing.  This file has to be installed and patched manually:
2479c609719bSwdenk
2480c609719bSwdenk	# cd /usr/pkg/cross/powerpc-netbsd/include
2481c609719bSwdenk	# mkdir powerpc
2482c609719bSwdenk	# ln -s powerpc machine
2483c609719bSwdenk	# cp /usr/src/sys/arch/powerpc/include/ansi.h powerpc/ansi.h
2484c609719bSwdenk	# ${EDIT} powerpc/ansi.h	## must remove __va_list, _BSD_VA_LIST
2485c609719bSwdenk
2486c609719bSwdenkNative builds *don't* work due to incompatibilities between native
2487c609719bSwdenkand U-Boot include files.
2488c609719bSwdenk
2489c609719bSwdenkBooting assumes that (the first part of) the image booted is a
2490c609719bSwdenkstage-2 loader which in turn loads and then invokes the kernel
2491c609719bSwdenkproper. Loader sources will eventually appear in the NetBSD source
2492c609719bSwdenktree (probably in sys/arc/mpc8xx/stand/u-boot_stage2/); in the
2493c609719bSwdenkmeantime, send mail to bruno@exet-ag.de and/or wd@denx.de for
2494c609719bSwdenkdetails.
2495c609719bSwdenk
2496c609719bSwdenk
2497c609719bSwdenkImplementation Internals:
2498c609719bSwdenk=========================
2499c609719bSwdenk
2500c609719bSwdenkThe following is not intended to be a complete description of every
2501c609719bSwdenkimplementation detail. However, it should help to understand the
2502c609719bSwdenkinner workings of U-Boot and make it easier to port it to custom
2503c609719bSwdenkhardware.
2504c609719bSwdenk
2505c609719bSwdenk
2506c609719bSwdenkInitial Stack, Global Data:
2507c609719bSwdenk---------------------------
2508c609719bSwdenk
2509c609719bSwdenkThe implementation of U-Boot is complicated by the fact that U-Boot
2510c609719bSwdenkstarts running out of ROM (flash memory), usually without access to
2511c609719bSwdenksystem RAM (because the memory controller is not initialized yet).
2512c609719bSwdenkThis means that we don't have writable Data or BSS segments, and BSS
2513c609719bSwdenkis not initialized as zero. To be able to get a C environment working
2514c609719bSwdenkat all, we have to allocate at least a minimal stack. Implementation
2515c609719bSwdenkoptions for this are defined and restricted by the CPU used: Some CPU
2516c609719bSwdenkmodels provide on-chip memory (like the IMMR area on MPC8xx and
2517c609719bSwdenkMPC826x processors), on others (parts of) the data cache can be
2518c609719bSwdenklocked as (mis-) used as memory, etc.
2519c609719bSwdenk
2520*43d9616cSwdenk	Chris Hallinan posted a good summy of  these  issues  to  the
2521*43d9616cSwdenk	u-boot-users mailing list:
2522*43d9616cSwdenk
2523*43d9616cSwdenk	Subject: RE: [U-Boot-Users] RE: More On Memory Bank x (nothingness)?
2524*43d9616cSwdenk	From: "Chris Hallinan" <clh@net1plus.com>
2525*43d9616cSwdenk	Date: Mon, 10 Feb 2003 16:43:46 -0500 (22:43 MET)
2526*43d9616cSwdenk	...
2527*43d9616cSwdenk
2528*43d9616cSwdenk	Correct me if I'm wrong, folks, but the way I understand it
2529*43d9616cSwdenk	is this: Using DCACHE as initial RAM for Stack, etc, does not
2530*43d9616cSwdenk	require any physical RAM backing up the cache. The cleverness
2531*43d9616cSwdenk	is that the cache is being used as a temporary supply of
2532*43d9616cSwdenk	necessary storage before the SDRAM controller is setup. It's
2533*43d9616cSwdenk	beyond the scope of this list to expain the details, but you
2534*43d9616cSwdenk	can see how this works by studying the cache architecture and
2535*43d9616cSwdenk	operation in the architecture and processor-specific manuals.
2536*43d9616cSwdenk
2537*43d9616cSwdenk	OCM is On Chip Memory, which I believe the 405GP has 4K. It
2538*43d9616cSwdenk	is another option for the system designer to use as an
2539*43d9616cSwdenk	initial stack/ram area prior to SDRAM being available. Either
2540*43d9616cSwdenk	option should work for you. Using CS 4 should be fine if your
2541*43d9616cSwdenk	board designers haven't used it for something that would
2542*43d9616cSwdenk	cause you grief during the initial boot! It is frequently not
2543*43d9616cSwdenk	used.
2544*43d9616cSwdenk
2545*43d9616cSwdenk	CFG_INIT_RAM_ADDR should be somewhere that won't interfere
2546*43d9616cSwdenk	with your processor/board/system design. The default value
2547*43d9616cSwdenk	you will find in any recent u-boot distribution in
2548*43d9616cSwdenk	Walnut405.h should work for you. I'd set it to a value larger
2549*43d9616cSwdenk	than your SDRAM module. If you have a 64MB SDRAM module, set
2550*43d9616cSwdenk	it above 400_0000. Just make sure your board has no resources
2551*43d9616cSwdenk	that are supposed to respond to that address! That code in
2552*43d9616cSwdenk	start.S has been around a while and should work as is when
2553*43d9616cSwdenk	you get the config right.
2554*43d9616cSwdenk
2555*43d9616cSwdenk	-Chris Hallinan
2556*43d9616cSwdenk	DS4.COM, Inc.
2557*43d9616cSwdenk
2558c609719bSwdenkIt is essential to remember this, since it has some impact on the C
2559c609719bSwdenkcode for the initialization procedures:
2560c609719bSwdenk
2561c609719bSwdenk* Initialized global data (data segment) is read-only. Do not attempt
2562c609719bSwdenk  to write it.
2563c609719bSwdenk
2564c609719bSwdenk* Do not use any unitialized global data (or implicitely initialized
2565c609719bSwdenk  as zero data - BSS segment) at all - this is undefined, initiali-
2566c609719bSwdenk  zation is performed later (when relocationg to RAM).
2567c609719bSwdenk
2568c609719bSwdenk* Stack space is very limited. Avoid big data buffers or things  like
2569c609719bSwdenk  that.
2570c609719bSwdenk
2571c609719bSwdenkHaving only the stack as writable memory limits means we cannot use
2572c609719bSwdenknormal global data to share information beween the code. But it
2573c609719bSwdenkturned out that the implementation of U-Boot can be greatly
2574c609719bSwdenksimplified by making a global data structure (gd_t) available to all
2575c609719bSwdenkfunctions. We could pass a pointer to this data as argument to _all_
2576c609719bSwdenkfunctions, but this would bloat the code. Instead we use a feature of
2577c609719bSwdenkthe GCC compiler (Global Register Variables) to share the data: we
2578c609719bSwdenkplace a pointer (gd) to the global data into a register which we
2579c609719bSwdenkreserve for this purpose.
2580c609719bSwdenk
2581c609719bSwdenkWhen chosing a register for such a purpose we are restricted  by  the
2582c609719bSwdenkrelevant  (E)ABI  specifications for the current architecture, and by
2583c609719bSwdenkGCC's implementation.
2584c609719bSwdenk
2585c609719bSwdenkFor PowerPC, the following registers have specific use:
2586c609719bSwdenk	R1:	stack pointer
2587c609719bSwdenk	R2:	TOC pointer
2588c609719bSwdenk	R3-R4:	parameter passing and return values
2589c609719bSwdenk	R5-R10:	parameter passing
2590c609719bSwdenk	R13:	small data area pointer
2591c609719bSwdenk	R30:	GOT pointer
2592c609719bSwdenk	R31:	frame pointer
2593c609719bSwdenk
2594c609719bSwdenk	(U-Boot also uses R14 as internal GOT pointer.)
2595c609719bSwdenk
2596c609719bSwdenk    ==> U-Boot will use R29 to hold a pointer to the global data
2597c609719bSwdenk
2598c609719bSwdenk    Note: on PPC, we could use a static initializer (since the
2599c609719bSwdenk    address of the global data structure is known at compile time),
2600c609719bSwdenk    but it turned out that reserving a register results in somewhat
2601c609719bSwdenk    smaller code - although the code savings are not that big (on
2602c609719bSwdenk    average for all boards 752 bytes for the whole U-Boot image,
2603c609719bSwdenk    624 text + 127 data).
2604c609719bSwdenk
2605c609719bSwdenkOn ARM, the following registers are used:
2606c609719bSwdenk
2607c609719bSwdenk	R0:	function argument word/integer result
2608c609719bSwdenk	R1-R3:	function argument word
2609c609719bSwdenk	R9:	GOT pointer
2610c609719bSwdenk	R10:	stack limit (used only if stack checking if enabled)
2611c609719bSwdenk	R11:	argument (frame) pointer
2612c609719bSwdenk	R12:	temporary workspace
2613c609719bSwdenk	R13:	stack pointer
2614c609719bSwdenk	R14:	link register
2615c609719bSwdenk	R15:	program counter
2616c609719bSwdenk
2617c609719bSwdenk    ==> U-Boot will use R8 to hold a pointer to the global data
2618c609719bSwdenk
2619c609719bSwdenk
2620c609719bSwdenk
2621c609719bSwdenkMemory Management:
2622c609719bSwdenk------------------
2623c609719bSwdenk
2624c609719bSwdenkU-Boot runs in system state and uses physical addresses, i.e. the
2625c609719bSwdenkMMU is not used either for address mapping nor for memory protection.
2626c609719bSwdenk
2627c609719bSwdenkThe available memory is mapped to fixed addresses using the memory
2628c609719bSwdenkcontroller. In this process, a contiguous block is formed for each
2629c609719bSwdenkmemory type (Flash, SDRAM, SRAM), even when it consists of several
2630c609719bSwdenkphysical memory banks.
2631c609719bSwdenk
2632c609719bSwdenkU-Boot is installed in the first 128 kB of the first Flash bank (on
2633c609719bSwdenkTQM8xxL modules this is the range 0x40000000 ... 0x4001FFFF). After
2634c609719bSwdenkbooting and sizing and initializing DRAM, the code relocates itself
2635c609719bSwdenkto the upper end of DRAM. Immediately below the U-Boot code some
2636c609719bSwdenkmemory is reserved for use by malloc() [see CFG_MALLOC_LEN
2637c609719bSwdenkconfiguration setting]. Below that, a structure with global Board
2638c609719bSwdenkInfo data is placed, followed by the stack (growing downward).
2639c609719bSwdenk
2640c609719bSwdenkAdditionally, some exception handler code is copied to the low 8 kB
2641c609719bSwdenkof DRAM (0x00000000 ... 0x00001FFF).
2642c609719bSwdenk
2643c609719bSwdenkSo a typical memory configuration with 16 MB of DRAM could look like
2644c609719bSwdenkthis:
2645c609719bSwdenk
2646c609719bSwdenk	0x0000 0000	Exception Vector code
2647c609719bSwdenk	      :
2648c609719bSwdenk	0x0000 1FFF
2649c609719bSwdenk	0x0000 2000	Free for Application Use
2650c609719bSwdenk	      :
2651c609719bSwdenk	      :
2652c609719bSwdenk
2653c609719bSwdenk	      :
2654c609719bSwdenk	      :
2655c609719bSwdenk	0x00FB FF20	Monitor Stack (Growing downward)
2656c609719bSwdenk	0x00FB FFAC	Board Info Data and permanent copy of global data
2657c609719bSwdenk	0x00FC 0000	Malloc Arena
2658c609719bSwdenk	      :
2659c609719bSwdenk	0x00FD FFFF
2660c609719bSwdenk	0x00FE 0000	RAM Copy of Monitor Code
2661c609719bSwdenk	...		eventually: LCD or video framebuffer
2662c609719bSwdenk	...		eventually: pRAM (Protected RAM - unchanged by reset)
2663c609719bSwdenk	0x00FF FFFF	[End of RAM]
2664c609719bSwdenk
2665c609719bSwdenk
2666c609719bSwdenkSystem Initialization:
2667c609719bSwdenk----------------------
2668c609719bSwdenk
2669c609719bSwdenkIn the reset configuration, U-Boot starts at the reset entry point
2670c609719bSwdenk(on most PowerPC systens at address 0x00000100). Because of the reset
2671c609719bSwdenkconfiguration for CS0# this is a mirror of the onboard Flash memory.
2672c609719bSwdenkTo be able to re-map memory U-Boot then jumps to it's link address.
2673c609719bSwdenkTo be able to implement the initialization code in C, a (small!)
2674c609719bSwdenkinitial stack is set up in the internal Dual Ported RAM (in case CPUs
2675c609719bSwdenkwhich provide such a feature like MPC8xx or MPC8260), or in a locked
2676c609719bSwdenkpart of the data cache. After that, U-Boot initializes the CPU core,
2677c609719bSwdenkthe caches and the SIU.
2678c609719bSwdenk
2679c609719bSwdenkNext, all (potentially) available memory banks are mapped using a
2680c609719bSwdenkpreliminary mapping. For example, we put them on 512 MB boundaries
2681c609719bSwdenk(multiples of 0x20000000: SDRAM on 0x00000000 and 0x20000000, Flash
2682c609719bSwdenkon 0x40000000 and 0x60000000, SRAM on 0x80000000). Then UPM A is
2683c609719bSwdenkprogrammed for SDRAM access. Using the temporary configuration, a
2684c609719bSwdenksimple memory test is run that determines the size of the SDRAM
2685c609719bSwdenkbanks.
2686c609719bSwdenk
2687c609719bSwdenkWhen there is more than one SDRAM bank, and the banks are of
2688c609719bSwdenkdifferent size, the larger is mapped first. For equal size, the first
2689c609719bSwdenkbank (CS2#) is mapped first. The first mapping is always for address
2690c609719bSwdenk0x00000000, with any additional banks following immediately to create
2691c609719bSwdenkcontiguous memory starting from 0.
2692c609719bSwdenk
2693c609719bSwdenkThen, the monitor installs itself at the upper end of the SDRAM area
2694c609719bSwdenkand allocates memory for use by malloc() and for the global Board
2695c609719bSwdenkInfo data; also, the exception vector code is copied to the low RAM
2696c609719bSwdenkpages, and the final stack is set up.
2697c609719bSwdenk
2698c609719bSwdenkOnly after this relocation will you have a "normal" C environment;
2699c609719bSwdenkuntil that you are restricted in several ways, mostly because you are
2700c609719bSwdenkrunning from ROM, and because the code will have to be relocated to a
2701c609719bSwdenknew address in RAM.
2702c609719bSwdenk
2703c609719bSwdenk
2704c609719bSwdenkU-Boot Porting Guide:
2705c609719bSwdenk----------------------
2706c609719bSwdenk
2707c609719bSwdenk[Based on messages by Jerry Van Baren in the U-Boot-Users mailing
27086aff3115Swdenklist, October 2002]
2709c609719bSwdenk
2710c609719bSwdenk
2711c609719bSwdenkint main (int argc, char *argv[])
2712c609719bSwdenk{
2713c609719bSwdenk	sighandler_t no_more_time;
2714c609719bSwdenk
2715c609719bSwdenk	signal (SIGALRM, no_more_time);
2716c609719bSwdenk	alarm (PROJECT_DEADLINE - toSec (3 * WEEK));
2717c609719bSwdenk
2718c609719bSwdenk	if (available_money > available_manpower) {
2719c609719bSwdenk		pay consultant to port U-Boot;
2720c609719bSwdenk		return 0;
2721c609719bSwdenk	}
2722c609719bSwdenk
2723c609719bSwdenk	Download latest U-Boot source;
2724c609719bSwdenk
27256aff3115Swdenk	Subscribe to u-boot-users mailing list;
27266aff3115Swdenk
2727c609719bSwdenk	if (clueless) {
2728c609719bSwdenk		email ("Hi, I am new to U-Boot, how do I get started?");
2729c609719bSwdenk	}
2730c609719bSwdenk
2731c609719bSwdenk	while (learning) {
2732c609719bSwdenk		Read the README file in the top level directory;
2733c609719bSwdenk		Read http://www.denx.de/re/DPLG.html
2734c609719bSwdenk		Read the source, Luke;
2735c609719bSwdenk	}
2736c609719bSwdenk
2737c609719bSwdenk	if (available_money > toLocalCurrency ($2500)) {
2738c609719bSwdenk		Buy a BDI2000;
2739c609719bSwdenk	} else {
2740c609719bSwdenk		Add a lot of aggravation and time;
2741c609719bSwdenk	}
2742c609719bSwdenk
2743c609719bSwdenk	Create your own board support subdirectory;
2744c609719bSwdenk
27456aff3115Swdenk	Create your own board config file;
27466aff3115Swdenk
2747c609719bSwdenk	while (!running) {
2748c609719bSwdenk		do {
2749c609719bSwdenk			Add / modify source code;
2750c609719bSwdenk		} until (compiles);
2751c609719bSwdenk		Debug;
2752c609719bSwdenk		if (clueless)
2753c609719bSwdenk			email ("Hi, I am having problems...");
2754c609719bSwdenk	}
2755c609719bSwdenk	Send patch file to Wolfgang;
2756c609719bSwdenk
2757c609719bSwdenk	return 0;
2758c609719bSwdenk}
2759c609719bSwdenk
2760c609719bSwdenkvoid no_more_time (int sig)
2761c609719bSwdenk{
2762c609719bSwdenk      hire_a_guru();
2763c609719bSwdenk}
2764c609719bSwdenk
2765c609719bSwdenk
2766c609719bSwdenk
2767c609719bSwdenkCoding Standards:
2768c609719bSwdenk-----------------
2769c609719bSwdenk
2770c609719bSwdenkAll contributions to U-Boot should conform to the Linux kernel
2771c609719bSwdenkcoding style; see the file "Documentation/CodingStyle" in your Linux
2772c609719bSwdenkkernel source directory.
2773c609719bSwdenk
2774c609719bSwdenkPlease note that U-Boot is implemented in C (and to some small parts
2775c609719bSwdenkin Assembler); no C++ is used, so please do not use C++ style
2776c609719bSwdenkcomments (//) in your code.
2777c609719bSwdenk
2778c609719bSwdenkSubmissions which do not conform to the standards may be returned
2779c609719bSwdenkwith a request to reformat the changes.
2780c609719bSwdenk
2781c609719bSwdenk
2782c609719bSwdenkSubmitting Patches:
2783c609719bSwdenk-------------------
2784c609719bSwdenk
2785c609719bSwdenkSince the number of patches for U-Boot is growing, we need to
2786c609719bSwdenkestablish some rules. Submissions which do not conform to these rules
2787c609719bSwdenkmay be rejected, even when they contain important and valuable stuff.
2788c609719bSwdenk
2789c609719bSwdenk
2790c609719bSwdenkWhen you send a patch, please include the following information with
2791c609719bSwdenkit:
2792c609719bSwdenk
2793c609719bSwdenk* For bug fixes: a description of the bug and how your patch fixes
2794c609719bSwdenk  this bug. Please try to include a way of demonstrating that the
2795c609719bSwdenk  patch actually fixes something.
2796c609719bSwdenk
2797c609719bSwdenk* For new features: a description of the feature and your
2798c609719bSwdenk  implementation.
2799c609719bSwdenk
2800c609719bSwdenk* A CHANGELOG entry as plaintext (separate from the patch)
2801c609719bSwdenk
2802c609719bSwdenk* For major contributions, your entry to the CREDITS file
2803c609719bSwdenk
2804c609719bSwdenk* When you add support for a new board, don't forget to add this
2805c609719bSwdenk  board to the MAKEALL script, too.
2806c609719bSwdenk
2807c609719bSwdenk* If your patch adds new configuration options, don't forget to
2808c609719bSwdenk  document these in the README file.
2809c609719bSwdenk
2810c609719bSwdenk* The patch itself. If you are accessing the CVS repository use "cvs
2811c609719bSwdenk  update; cvs diff -puRN"; else, use "diff -purN OLD NEW". If your
2812c609719bSwdenk  version of diff does not support these options, then get the latest
2813c609719bSwdenk  version of GNU diff.
2814c609719bSwdenk
2815c609719bSwdenk  We accept patches as plain text, MIME attachments or as uuencoded
2816c609719bSwdenk  gzipped text.
2817c609719bSwdenk
2818c609719bSwdenkNotes:
2819c609719bSwdenk
2820c609719bSwdenk* Before sending the patch, run the MAKEALL script on your patched
2821c609719bSwdenk  source tree and make sure that no errors or warnings are reported
2822c609719bSwdenk  for any of the boards.
2823c609719bSwdenk
2824c609719bSwdenk* Keep your modifications to the necessary minimum: A patch
2825c609719bSwdenk  containing several unrelated changes or arbitrary reformats will be
2826c609719bSwdenk  returned with a request to re-formatting / split it.
2827c609719bSwdenk
2828c609719bSwdenk* If you modify existing code, make sure that your new code does not
2829c609719bSwdenk  add to the memory footprint of the code ;-) Small is beautiful!
2830c609719bSwdenk  When adding new features, these should compile conditionally only
2831c609719bSwdenk  (using #ifdef), and the resulting code with the new feature
2832c609719bSwdenk  disabled must not need more memory than the old code without your
2833c609719bSwdenk  modification.
2834