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
19 * You can also choose to distribute this program under the terms of
20 * the Unmodified Binary Distribution Licence (as given in the file
21 * COPYING.UBDL), provided that you have satisfied its requirements.
24 FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
30 * The debug port is supported by bochs (via the "port_e9_hack"
31 * configuration file directive) and by qemu (via the "-debugcon"
32 * command-line option).
37 #include <ipxe/console.h>
38 #include <ipxe/init.h>
39 #include <config/console.h>
42 #define DEBUG_PORT 0xe9
44 /** Debug port installation check magic value */
45 #define DEBUG_PORT_CHECK 0xe9
47 /* Set default console usage if applicable */
48 #if ! ( defined ( CONSOLE_DEBUGCON ) && CONSOLE_EXPLICIT ( CONSOLE_DEBUGCON ) )
49 #undef CONSOLE_DEBUGCON
50 #define CONSOLE_DEBUGCON ( CONSOLE_USAGE_ALL & ~CONSOLE_USAGE_TUI )
54 * Print a character to debug port console
56 * @v character Character to be printed
58 static void debugcon_putchar ( int character ) {
60 /* Write character to debug port */
61 outb ( character, DEBUG_PORT );
64 /** Debug port console driver */
65 struct console_driver debugcon_console __console_driver = {
66 .putchar = debugcon_putchar,
67 .usage = CONSOLE_DEBUGCON,
71 * Initialise debug port console
74 static void debugcon_init ( void ) {
77 /* Check if console is present */
78 check = inb ( DEBUG_PORT );
79 if ( check != DEBUG_PORT_CHECK ) {
80 DBG ( "Debug port not present; disabling console\n" );
81 debugcon_console.disabled = CONSOLE_DISABLED;
86 * Debug port console initialisation function
88 struct init_fn debugcon_init_fn __init_fn ( INIT_EARLY ) = {
89 .initialise = debugcon_init,