serial.c revision c58f1213e628a545081c70e26c6b67a841cff880
/*
* Copyright (C) 2006-2012 Oracle Corporation
*
* This file is part of VirtualBox Open Source Edition (OSE), as
* available from http://www.virtualbox.org. This file is free software;
* you can redistribute it and/or modify it under the terms of the GNU
* General Public License (GPL) as published by the Free Software
* Foundation, in version 2 as it comes in the "COPYING" file of the
* VirtualBox OSE distribution. VirtualBox OSE is distributed in the
* hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
* --------------------------------------------------------------------
*
* This code is based on:
*
* ROM BIOS for use with Bochs/Plex86/QEMU emulation environment
*
* Copyright (C) 2002 MandrakeSoft S.A.
*
* MandrakeSoft S.A.
* 43, rue d'Aboukir
* 75002 Paris - France
* http://www.linux-mandrake.com/
* http://www.mandrakesoft.com/
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <stdint.h>
#include "inlines.h"
#include "biosint.h"
void BIOSCALL int14_function(pusha_regs_t regs, uint16_t es, uint16_t ds, volatile iret_addr_t iret_addr)
{
uint16_t addr, timer, val16;
uint8_t timeout;
int_enable();
addr = read_word(0x0040, (regs.u.r16.dx << 1));
timeout = read_byte(0x0040, 0x007C + regs.u.r16.dx);
if ((regs.u.r16.dx < 4) && (addr > 0)) {
switch (regs.u.r8.ah) {
case 0:
outb(addr+3, inb(addr+3) | 0x80);
if (regs.u.r8.al & 0xE0 == 0) {
outb(addr, 0x17);
outb(addr+1, 0x04);
} else {
val16 = 0x600 >> ((regs.u.r8.al & 0xE0) >> 5);
outb(addr, val16 & 0xFF);
outb(addr+1, val16 >> 8);
}
outb(addr+3, regs.u.r8.al & 0x1F);
regs.u.r8.ah = inb(addr+5);
regs.u.r8.al = inb(addr+6);
ClearCF(iret_addr.flags);
break;
case 1:
timer = read_word(0x0040, 0x006C);
while (((inb(addr+5) & 0x60) != 0x60) && (timeout)) {
val16 = read_word(0x0040, 0x006C);
if (val16 != timer) {
timer = val16;
timeout--;
}
}
if (timeout) outb(addr, regs.u.r8.al);
regs.u.r8.ah = inb(addr+5);
if (!timeout) regs.u.r8.ah |= 0x80;
ClearCF(iret_addr.flags);
break;
case 2:
timer = read_word(0x0040, 0x006C);
while (((inb(addr+5) & 0x01) == 0) && (timeout)) {
val16 = read_word(0x0040, 0x006C);
if (val16 != timer) {
timer = val16;
timeout--;
}
}
if (timeout) {
regs.u.r8.ah = 0;
regs.u.r8.al = inb(addr);
} else {
regs.u.r8.ah = inb(addr+5);
}
ClearCF(iret_addr.flags);
break;
case 3:
regs.u.r8.ah = inb(addr+5);
regs.u.r8.al = inb(addr+6);
ClearCF(iret_addr.flags);
break;
default:
SetCF(iret_addr.flags); // Unsupported
}
} else {
SetCF(iret_addr.flags); // Unsupported
}
}