/* * vesabios.S * DANG_BEGIN_MODULE * * REMARK * The VGA/VESA BIOS for VGAEmu. * * This is what DOS applications see as their video BIOS. It will be * mapped at 0xc000:0x0000 and typically be less than one page in size. * This video BIOS is write-protected, write accesses to this memory * are emulated by vesa_emu_fault() in env/video/vesa.c. * * It doesn't have much functionality, just stores the VESA mode table * and the protected mode interface necessary for VESA BIOS Extension (VBE) * support and the VGA fonts. * * Note that the video BIOS is extended by vbe_init() in env/video/vesa.c. * * /REMARK * DANG_END_MODULE * * This is vgaemu's VESA BIOS (C000:0 .. C800:0) * * Copyright (C) 1995 1996, Erik Mouw and Arjan Filius * * * 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., 675 Mass Ave, Cambridge, MA 02139, USA. * * * email: J.A.K.Mouw@et.tudelft.nl, I.A.Filius@et.tudelft.nl * * * DANG_BEGIN_CHANGELOG * * 1997/07/07: Did some cleaning up and removed lots of #define's. Some * parts are now dynamically configurable; they are set up in vbe_init() * in env/video/vesa.c. * -- sw (Steffen Winterfeldt ) * * 2001/01/17: Converted to gas. Bart Oldeman . * * DANG_END_CHANGELOG * * * We must compile this with gas/ld as follows: * gcc -E vesabios.S >vesabios.s * as -o vesabios.o vesabios.s * */ #include "memory.h" .code16 .text .globl _start16 _start16: .globl vgaemu_bios_start .globl vgaemu_bios_prod_name .globl vgaemu_bios_win_func .globl vgaemu_bios_end vgaemu_bios_start: .byte 0x55, 0xaa /* BIOS signature, required for BIOS extensions */ .byte 0x00 /* BIOS extension length in units of 512 bytes */ lret /* BIOS init function */ nop vgaemu_bios_prod_name: .ascii "DOSEMU VGA/VBE 2.0 Emulator" .byte 0x00 .ascii "DOSEMU VGAemu. (C) 1995 1996, " .ascii "I.A. Filius and J.A.K. Mouw" .byte 0x00 .ascii "VESA BIOS Extensions V2.0 for DOSEMU." .byte 0x0d, 0x0a .ascii "Copyright (c) 1997 Steffen Winterfeldt" .byte 0x00 vgaemu_bios_win_func: pushw %bx /* 0x40 is our own special code, (cf. vesa.c), * make it 0x00 if you think it causes problems */ orb $0x40,%bh mov $0x4f05,%ax int $0x10 popw %bx lret vgaemu_bios_end: #ifdef __ELF__ .section .note.GNU-stack,"",%progbits #endif