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First CVS upload.

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Imported-from: https://svn.code.sf.net/p/dosbox/code-0/dosbox/trunk@80
This commit is contained in:
Sjoerd van der Berg 2002-07-27 13:08:48 +00:00
parent 7d1ca9bdd4
commit 42e5d0b779
158 changed files with 42940 additions and 0 deletions
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src/cpu/callback.cpp Normal file
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/*
* Copyright (C) 2002 The DOSBox Team
*
* 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 Library 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <stdlib.h>
#include <stdio.h>
#include "dosbox.h"
#include "callback.h"
#include "mem.h"
#include "cpu.h"
/* CallBack are located at 0xC800:0
And they are 16 bytes each and you can define them to behave in certain ways like a
far return or and IRET
*/
CallBack_Handler CallBack_Handlers[CB_MAX];
static Bitu call_runint16,call_idle,call_default,call_runfar16;
static Bitu illegal_handler(void) {
E_Exit("Illegal CallBack Called");
return 1;
}
Bitu CALLBACK_Allocate(void) {
for (Bitu i=0;(i<CB_MAX);i++) {
if (CallBack_Handlers[i]==&illegal_handler) {
CallBack_Handlers[i]=0;
return i;
}
}
E_Exit("CALLBACK:Can't allocate handler.");
return 0;
}
void CALLBACK_Idle(void) {
/* this makes the cpu execute instructions to handle irq's and then come back */
Bit16u oldcs=Segs[cs].value;
Bit32u oldeip=reg_eip;
SetSegment_16(cs,CB_SEG);
reg_eip=call_idle<<4;
DOSBOX_RunMachine();
reg_eip=oldeip;
SetSegment_16(cs,oldcs);
}
static Bitu default_handler(void) {
LOG_WARN("Illegal Unhandled Interrupt Called %d",lastint);
return CBRET_NONE;
};
static Bitu stop_handler(void) {
return CBRET_STOP;
};
void CALLBACK_RunRealFar(Bit16u seg,Bit16u off) {
real_writew((Bit16u)CB_SEG,(call_runfar16<<4)+1,off);
real_writew((Bit16u)CB_SEG,(call_runfar16<<4)+3,seg);
Bit32u oldeip=reg_eip;
Bit16u oldcs=Segs[cs].value;
reg_eip=call_runfar16<<4;
SetSegment_16(cs,CB_SEG);
DOSBOX_RunMachine();
reg_eip=oldeip;
SetSegment_16(cs,oldcs);
}
void CALLBACK_RunRealInt(Bit8u intnum) {
real_writeb((Bit16u)CB_SEG,(call_runint16<<4)+1,intnum);
Bit32u oldeip=reg_eip;
Bit16u oldcs=Segs[cs].value;
reg_eip=call_runint16<<4;
SetSegment_16(cs,CB_SEG);
DOSBOX_RunMachine();
reg_eip=oldeip;
SetSegment_16(cs,oldcs);
}
void CALLBACK_SZF(bool val) {
Bit16u tempf=real_readw(Segs[ss].value,reg_sp+4) & 0xFFBF;
Bit16u newZF=(val==true) << 6;
real_writew(Segs[ss].value,reg_sp+4,(tempf | newZF));
};
void CALLBACK_SCF(bool val) {
Bit16u tempf=real_readw(Segs[ss].value,reg_sp+4) & 0xFFFE;
Bit16u newCF=(val==true);
real_writew(Segs[ss].value,reg_sp+4,(tempf | newCF));
};
bool CALLBACK_Setup(Bitu callback,CallBack_Handler handler,Bitu type) {
if (callback>=CB_MAX) return false;
switch (type) {
case CB_RETF:
real_writeb((Bit16u)CB_SEG,(callback<<4),(Bit8u)0xFE); //GRP 4
real_writeb((Bit16u)CB_SEG,(callback<<4)+1,(Bit8u)0x38); //Extra Callback instruction
real_writew((Bit16u)CB_SEG,(callback<<4)+2,callback); //The immediate word
real_writeb((Bit16u)CB_SEG,(callback<<4)+4,(Bit8u)0xCB); //A RETF Instruction
break;
case CB_IRET:
real_writeb((Bit16u)CB_SEG,(callback<<4),(Bit8u)0xFE); //GRP 4
real_writeb((Bit16u)CB_SEG,(callback<<4)+1,(Bit8u)0x38); //Extra Callback instruction
real_writew((Bit16u)CB_SEG,(callback<<4)+2,callback); //The immediate word
real_writeb((Bit16u)CB_SEG,(callback<<4)+4,(Bit8u)0xCF); //An IRET Instruction
break;
default:
E_Exit("CALLBACK:Setup:Illegal type %d",type);
}
CallBack_Handlers[callback]=handler;
return true;
}
void CALLBACK_Init(void) {
Bitu i;
for (i=0;i<CB_MAX;i++) {
CallBack_Handlers[i]=&illegal_handler;
}
/* Setup the Software interrupt handler */
call_runint16=CALLBACK_Allocate();
CallBack_Handlers[call_runint16]=stop_handler;
real_writeb((Bit16u)CB_SEG,(call_runint16<<4),0xCD);
real_writeb((Bit16u)CB_SEG,(call_runint16<<4)+2,0xFE);
real_writeb((Bit16u)CB_SEG,(call_runint16<<4)+3,0x38);
real_writew((Bit16u)CB_SEG,(call_runint16<<4)+4,call_runint16);
/* Setup the Far Call handler */
call_runfar16=CALLBACK_Allocate();
CallBack_Handlers[call_runfar16]=stop_handler;
real_writeb((Bit16u)CB_SEG,(call_runfar16<<4),0x9A);
real_writeb((Bit16u)CB_SEG,(call_runfar16<<4)+5,0xFE);
real_writeb((Bit16u)CB_SEG,(call_runfar16<<4)+6,0x38);
real_writew((Bit16u)CB_SEG,(call_runfar16<<4)+7,call_runfar16);
/* Setup the idle handler */
call_idle=CALLBACK_Allocate();
CallBack_Handlers[call_idle]=stop_handler;
for (i=0;i<=11;i++) real_writeb((Bit16u)CB_SEG,(call_idle<<4)+i,0x90);
real_writeb((Bit16u)CB_SEG,(call_idle<<4)+12,0xFE);
real_writeb((Bit16u)CB_SEG,(call_idle<<4)+13,0x38);
real_writew((Bit16u)CB_SEG,(call_idle<<4)+14,call_idle);
/* Setup all Interrupt to point to the default handler */
call_default=CALLBACK_Allocate();
CALLBACK_Setup(call_default,&default_handler,CB_IRET);
for (i=0;i<256;i++) {
real_writed(0,i*4,CALLBACK_RealPointer(call_default));
}
}