/* * Copyright (C) 2006 Michael Brown . * * 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 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., 675 Mass Ave, Cambridge, MA 02139, USA. */ #include #include /** * Print a character to BIOS console * * @v character Character to be printed */ static void bios_putchar ( int character ) { __asm__ __volatile__ ( REAL_CODE ( "sti\n\t" "int $0x10\n\t" "cli\n\t" ) : : "a" ( character | 0x0e00 ), "b" ( 1 ) : "ebp" ); } /** * Get character from BIOS console * * @ret character Character read from console */ static int bios_getchar ( void ) { uint8_t character; __asm__ __volatile__ ( REAL_CODE ( "sti\n\t" "int $0x16\n\t" "cli\n\t" ) : "=a" ( character ) : "a" ( 0x0000 ) ); return character; } /** * Check for character ready to read from BIOS console * * @ret True Character available to read * @ret False No character available to read */ static int bios_iskey ( void ) { unsigned int discard_a; unsigned int flags; __asm__ __volatile__ ( REAL_CODE ( "sti\n\t" "int $0x16\n\t" "pushfw\n\t" "popw %w0\n\t" "cli\n\t" ) : "=r" ( flags ), "=a" ( discard_a ) : "a" ( 0x0001 ) ); return ( ! ( flags & ZF ) ); } struct console_driver bios_console __console_driver = { .putchar = bios_putchar, .getchar = bios_getchar, .iskey = bios_iskey, };