Files
blueMSX-Core/Core/Memory/romMapperTurboRTimer.c

133 lines
3.5 KiB
C
Executable File

/*****************************************************************************
** $Source: /cygdrive/d/Private/_SVNROOT/bluemsx/blueMSX/Src/Memory/romMapperTurboRTimer.c,v $
**
** $Revision: 1.5 $
**
** $Date: 2008-03-30 18:38:44 $
**
** More info: http://www.bluemsx.com
**
** Copyright (C) 2003-2006 Daniel Vik
**
** 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.
**
******************************************************************************
*/
#include "romMapperTurboRTimer.h"
#include "MediaDb.h"
#include "DeviceManager.h"
#include "SaveState.h"
#include "Board.h"
#include "IoPort.h"
#include <stdlib.h>
#include <string.h>
#include <stdio.h>
typedef struct {
int deviceHandle;
UInt32 counter;
UInt32 refTime;
UInt32 refFrag;
} RomMapperTurboRTimer;
static RomMapperTurboRTimer* theTimer = NULL;
static void saveState(RomMapperTurboRTimer* rm)
{
SaveState* state = saveStateOpenForWrite("mapperTurboRTimer");
saveStateSet(state, "counter", rm->counter);
saveStateSet(state, "refTime", rm->refTime);
saveStateSet(state, "refFrag", rm->refFrag);
saveStateClose(state);
}
static void loadState(RomMapperTurboRTimer* rm)
{
SaveState* state = saveStateOpenForRead("mapperTurboRTimer");
rm->counter = saveStateGet(state, "counter", 0);
rm->refTime = saveStateGet(state, "refTime", boardSystemTime());
rm->refFrag = saveStateGet(state, "refFrag", 0);
saveStateClose(state);
}
static void destroy(RomMapperTurboRTimer* rm)
{
deviceManagerUnregister(rm->deviceHandle);
ioPortUnregister(0xe6);
ioPortUnregister(0xe7);
free(rm);
theTimer = NULL;
}
void romMapperTurboRTimerSync()
{
if (theTimer != NULL) {
UInt32 systemTime = boardSystemTime();
UInt64 elapsed = 255682 * (UInt64)(systemTime - theTimer->refTime) + theTimer->refFrag;
theTimer->refTime = systemTime;
theTimer->refFrag = (UInt32)(elapsed % boardFrequency());
theTimer->counter += (UInt32)(elapsed / boardFrequency());
}
}
static UInt8 read(RomMapperTurboRTimer* rm, UInt16 ioPort)
{
romMapperTurboRTimerSync();
switch (ioPort & 0x01) {
case 0:
return (UInt8)(rm->counter & 0xff);
case 1:
return (UInt8)((rm->counter >> 8) & 0xff);
}
return 0xff;
}
static void write(RomMapperTurboRTimer* rm, UInt16 ioPort, UInt8 value)
{
theTimer->counter = 0;
rm->refTime = boardSystemTime();
rm->refFrag = 0;
}
int romMapperTurboRTimerCreate()
{
DeviceCallbacks callbacks = { destroy, NULL, saveState, loadState };
RomMapperTurboRTimer* rm = malloc(sizeof(RomMapperTurboRTimer));
rm->deviceHandle = deviceManagerRegister(ROM_TURBORTIMER, &callbacks, rm);
rm->refTime = boardSystemTime();
rm->refFrag = 0;
rm->counter = 0;
ioPortRegister(0xe6, read, write, rm);
ioPortRegister(0xe7, read, write, rm);
theTimer = rm;
return 1;
}