2 * Copyright (C) 2012 Michael Brown <mbrown@fensystems.co.uk>.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation; either version 2 of the
7 * License, or (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
20 FILE_LICENCE ( GPL2_OR_LATER );
26 * The debug port is supported by bochs (via the "port_e9_hack"
27 * configuration file directive) and by qemu (via the "-debugcon"
28 * command-line option).
33 #include <ipxe/console.h>
34 #include <ipxe/init.h>
35 #include <config/console.h>
38 #define DEBUG_PORT 0xe9
40 /** Debug port installation check magic value */
41 #define DEBUG_PORT_CHECK 0xe9
43 /* Set default console usage if applicable */
44 #if ! ( defined ( CONSOLE_DEBUGCON ) && CONSOLE_EXPLICIT ( CONSOLE_DEBUGCON ) )
45 #undef CONSOLE_DEBUGCON
46 #define CONSOLE_DEBUGCON ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )
50 * Print a character to debug port console
52 * @v character Character to be printed
54 static void debugcon_putchar ( int character ) {
56 /* Write character to debug port */
57 outb ( character, DEBUG_PORT );
60 /** Debug port console driver */
61 struct console_driver debugcon_console __console_driver = {
62 .putchar = debugcon_putchar,
63 .usage = CONSOLE_DEBUGCON,
67 * Initialise debug port console
70 static void debugcon_init ( void ) {
73 /* Check if console is present */
74 check = inb ( DEBUG_PORT );
75 if ( check != DEBUG_PORT_CHECK ) {
76 DBG ( "Debug port not present; disabling console\n" );
77 debugcon_console.disabled = CONSOLE_DISABLED;
82 * Debug port console initialisation function
84 struct init_fn debugcon_init_fn __init_fn ( INIT_EARLY ) = {
85 .initialise = debugcon_init,