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diff --git a/doc/README.console b/doc/README.console new file mode 100644 index 000000000..6d477df75 --- /dev/null +++ b/doc/README.console @@ -0,0 +1,118 @@ +/* + * (C) Copyright 2000 + * Paolo Scaffardi, AIRVENT SAM s.p.a - RIMINI(ITALY), arsenio@tin.it + * + * See file CREDITS for list of people who contributed to this + * project. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + +U-Boot console handling +======================== + +HOW THE CONSOLE WORKS? +---------------------- + +At system startup U-Boot initializes a serial console. When U-Boot +relocates itself to RAM, all console drivers are initialized (they +will register all detected console devices to the system for further +use). + +If not defined in the environment, the first input device is assigned +to the 'stdin' file, the first output one to 'stdout' and 'stderr'. + +You can use the command "coninfo" to see all registered console +devices and their flags. You can assign a standard file (stdin, +stdout or stderr) to any device you see in that list simply by +assigning its name to the corresponding environment variable. For +example: + + setenv stdin wl_kbd <- To use the wireless keyboard + setenv stdout video <- To use the video console + +Do a simple "saveenv" to save the console settings in the environment +and get them working on the next startup, too. + +HOW CAN I USE STANDARD FILE INTO THE SOURCES? +--------------------------------------------- + +You can use the following functions to access the console: + +* STDOUT: + putc (to put a char to stdout) + puts (to put a string to stdout) + printf (to format and put a string to stdout) + +* STDIN: + tstc (to test for the presence of a char in stdin) + getc (to get a char from stdin) + +* STDERR: + eputc (to put a char to stderr) + eputs (to put a string to stderr) + eprintf (to format and put a string to stderr) + +* FILE (can be 'stdin', 'stdout', 'stderr'): + fputc (like putc but redirected to a file) + fputs (like puts but redirected to a file) + fprintf (like printf but redirected to a file) + ftstc (like tstc but redirected to a file) + fgetc (like getc but redirected to a file) + +Remember that all FILE-related functions CANNOT be used before +U-Boot relocation (done in 'board_init_r' in common/board.c). + +HOW CAN I USE STANDARD FILE INTO APPLICATIONS? +---------------------------------------------- + +Use the 'bd_mon_fnc' field of the bd_t structure passed to the +application to do everything you want with the console. + +But REMEMBER that that will work only if you have not overwritten any +U-Boot code while loading (or uncompressing) the image of your +application. + +For example, you won't get the console stuff running in the Linux +kernel because the kernel overwrites U-Boot before running. Only +some parameters like the framebuffer descriptors are passed to the +kernel in the high memory area to let the applications (the kernel) +use the framebuffers initialized by U-Boot. + +SUPPORTED DRIVERS +----------------- + +Working drivers: + + serial (architecture dependent serial stuff) + video (mpc8xx video controller) + +Work in progress: + + wl_kbd (Wireless 4PPM keyboard) + +Waiting for volounteers: + + lcd (mpc8xx lcd controller; to ) + +TESTED CONFIGURATIONS +--------------------- + +The driver has been tested with the following configurations (see +CREDITS for other contact informations): + +- MPC823FADS with AD7176 on a PAL TV (YCbYCr) - arsenio@tin.it +- GENIETV with AD7177 on a PAL TV (YCbYCr) - arsenio@tin.it |