blob: 60de61f55da512e3728ce630e6f567e6c124d9fb [file] [log] [blame]
/*
* Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
/** @file
*
* Debug port console
*
* The debug port is supported by bochs (via the "port_e9_hack"
* configuration file directive) and by qemu (via the "-debugcon"
* command-line option).
*/
#include <stdint.h>
#include <ipxe/io.h>
#include <ipxe/console.h>
#include <ipxe/init.h>
#include <config/console.h>
/** Debug port */
#define DEBUG_PORT 0xe9
/** Debug port installation check magic value */
#define DEBUG_PORT_CHECK 0xe9
/* Set default console usage if applicable */
#if ! ( defined ( CONSOLE_DEBUGCON ) && CONSOLE_EXPLICIT ( CONSOLE_DEBUGCON ) )
#undef CONSOLE_DEBUGCON
#define CONSOLE_DEBUGCON ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )
#endif
/**
* Print a character to debug port console
*
* @v character Character to be printed
*/
static void debugcon_putchar ( int character ) {
/* Write character to debug port */
outb ( character, DEBUG_PORT );
}
/** Debug port console driver */
struct console_driver debugcon_console __console_driver = {
.putchar = debugcon_putchar,
.usage = CONSOLE_DEBUGCON,
};
/**
* Initialise debug port console
*
*/
static void debugcon_init ( void ) {
uint8_t check;
/* Check if console is present */
check = inb ( DEBUG_PORT );
if ( check != DEBUG_PORT_CHECK ) {
DBG ( "Debug port not present; disabling console\n" );
debugcon_console.disabled = CONSOLE_DISABLED;
}
}
/**
* Debug port console initialisation function
*/
struct init_fn debugcon_init_fn __init_fn ( INIT_EARLY ) = {
.initialise = debugcon_init,
};