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[NTVDM]

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Implement Programmable Interval Timer (PIT) emulation. Fix bugs in interrupts and PIC emulation.


svn path=/branches/ntvdm/; revision=59271
This commit is contained in:
Aleksandar Andrejevic 2013-06-21 00:47:07 +00:00
parent 7765319949
commit da877e495e
4 changed files with 219 additions and 12 deletions
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11
subsystems/ntvdm/bios.c
View file

@ -71,6 +71,12 @@ BOOLEAN BiosInitialize()
/* Make sure the PIC is in 8086 mode */
PicWriteData(PIC_MASTER_DATA, PIC_ICW4_8086);
PicWriteData(PIC_SLAVE_DATA, PIC_ICW4_8086);
/* Clear the masks for both PICs */
PicWriteData(PIC_MASTER_DATA, 0x00);
PicWriteData(PIC_SLAVE_DATA, 0x00);
PitInitialize();
return TRUE;
}
@ -251,4 +257,9 @@ VOID BiosVideoService()
}
}
VOID BiosHandleIrq(BYTE IrqNumber)
{
PicWriteCommand(PIC_MASTER_CMD, PIC_OCW2_EOI);
}
/* EOF */

64
subsystems/ntvdm/emulator.c
View file

@ -56,12 +56,58 @@ static VOID EmulatorWriteMemory(PVOID Context, UINT Address, LPBYTE Buffer, INT
static VOID EmulatorReadIo(PVOID Context, UINT Address, LPBYTE Buffer, INT Size)
{
// TODO: NOT IMPLEMENTED!
switch (Address)
{
case PIC_MASTER_CMD:
case PIC_SLAVE_CMD:
{
*Buffer = PicReadCommand(Address);
break;
}
case PIC_MASTER_DATA:
case PIC_SLAVE_DATA:
{
*Buffer = PicReadData(Address);
break;
}
}
}
static VOID EmulatorWriteIo(PVOID Context, UINT Address, LPBYTE Buffer, INT Size)
{
// TODO: NOT IMPLEMENTED!
BYTE Byte = *Buffer;
switch (Address)
{
case PIT_COMMAND_PORT:
{
PitWriteCommand(Byte);
break;
}
case PIT_DATA_PORT(0):
case PIT_DATA_PORT(1):
case PIT_DATA_PORT(2):
{
PitWriteData(Address - PIT_DATA_PORT(0), Byte);
break;
}
case PIC_MASTER_CMD:
case PIC_SLAVE_CMD:
{
PicWriteCommand(Address, Byte);
break;
}
case PIC_MASTER_DATA:
case PIC_SLAVE_DATA:
{
PicWriteData(Address, Byte);
break;
}
}
}
static VOID EmulatorSoftwareInt(PVOID Context, BYTE Number)
@ -101,6 +147,18 @@ static VOID EmulatorSoftwareInt(PVOID Context, BYTE Number)
VdmRunning = FALSE;
return;
}
/* Check if this was an PIC IRQ */
if (IntNum >= BIOS_PIC_MASTER_INT && IntNum < BIOS_PIC_MASTER_INT + 8)
{
/* It was an IRQ from the master PIC */
BiosHandleIrq(IntNum - BIOS_PIC_MASTER_INT);
}
else if (IntNum >= BIOS_PIC_SLAVE_INT && IntNum < BIOS_PIC_SLAVE_INT + 8)
{
/* It was an IRQ from the slave PIC */
BiosHandleIrq(IntNum - BIOS_PIC_SLAVE_INT + 8);
}
switch (IntNum)
{
@ -183,7 +241,7 @@ VOID EmulatorExecute(WORD Segment, WORD Offset)
VOID EmulatorInterrupt(BYTE Number)
{
LPWORD IntVecTable = (LPWORD)((ULONG_PTR)BaseAddress);
LPDWORD IntVecTable = (LPDWORD)((ULONG_PTR)BaseAddress);
UINT Segment, Offset;
/* Get the segment and offset */

152
subsystems/ntvdm/hardware.c
View file

@ -24,7 +24,64 @@ typedef struct _PIC
BOOLEAN ReadIsr;
} PIC, *PPIC;
typedef struct _PIT_CHANNEL
{
BOOLEAN RateGenerator;
BOOLEAN Pulsed;
BOOLEAN FlipFlop;
BYTE AccessMode;
WORD ReloadValue;
} PIT_CHANNEL, *PPIT_CHANNEL;
static PIC MasterPic, SlavePic;
static PIT_CHANNEL PitChannels[PIT_CHANNELS];
static DWORD WINAPI PitThread(PVOID Parameter)
{
LARGE_INTEGER Frequency, CurrentTime, LastTickTime;
LONGLONG Elapsed, Milliseconds, TicksNeeded;
UNREFERENCED_PARAMETER(Parameter);
/* Get the performance counter frequency */
if (!QueryPerformanceFrequency(&Frequency)) return EXIT_FAILURE;
if (!QueryPerformanceCounter(&LastTickTime)) return EXIT_FAILURE;
while (VdmRunning)
{
if (!QueryPerformanceCounter(&CurrentTime)) return EXIT_FAILURE;
/* Calculate the elapsed time, in PIT ticks */
Elapsed = ((CurrentTime.QuadPart - LastTickTime.QuadPart)
* PIT_BASE_FREQUENCY)
/ Frequency.QuadPart;
/* A reload value of 0 indicates 65536 */
if (PitChannels[0].ReloadValue) TicksNeeded = PitChannels[0].ReloadValue;
else TicksNeeded = 65536;
if (Elapsed < TicksNeeded)
{
/* Get the number of milliseconds */
Milliseconds = (Elapsed * 1000LL) / PIT_BASE_FREQUENCY;
/* If this number is non-zero, put the thread in the waiting state */
if (Milliseconds > 0LL) Sleep((DWORD)Milliseconds);
continue;
}
LastTickTime = CurrentTime;
/* Do the IRQ */
if (PitChannels[0].RateGenerator || !PitChannels[0].Pulsed)
{
PitChannels[0].Pulsed = TRUE;
PicInterruptRequest(0);
}
}
return EXIT_SUCCESS;
}
/* PUBLIC FUNCTIONS ***********************************************************/
@ -165,14 +222,15 @@ VOID PicInterruptRequest(BYTE Number)
{
if (Number >= 0 && Number < 8)
{
/* Check if the interrupt is busy or in a cascade */
/* Check if the interrupt is busy, in a cascade or masked */
if (MasterPic.CascadeRegister & (1 << Number)
|| MasterPic.InServiceRegister & (1 << Number))
|| MasterPic.InServiceRegister & (1 << Number)
|| MasterPic.MaskRegister & (1 << Number))
{
return;
}
MasterPic.InServiceRegister |= 1 << Number;
if (!MasterPic.AutoEoi) MasterPic.InServiceRegister |= 1 << Number;
EmulatorInterrupt(MasterPic.IntOffset + Number);
}
else if (Number >= 8 && Number < 16)
@ -189,20 +247,96 @@ VOID PicInterruptRequest(BYTE Number)
return;
}
/* Check the if the slave PIC is busy */
if (MasterPic.InServiceRegister & (1 << 2)) return;
/* Check the if the slave PIC is busy or masked */
if (MasterPic.InServiceRegister & (1 << 2)
|| MasterPic.MaskRegister & (1 << 2)) return;
/* Set the IRQ 2 bit in the master ISR */
MasterPic.InServiceRegister |= 1 << 2;
if (!MasterPic.AutoEoi) MasterPic.InServiceRegister |= 1 << 2;
/* Check if the interrupt is busy or in a cascade */
/* Check if the interrupt is busy, in a cascade or masked */
if (SlavePic.CascadeRegister & (1 << Number)
|| SlavePic.InServiceRegister & (1 << Number))
|| SlavePic.InServiceRegister & (1 << Number)
|| SlavePic.MaskRegister & (1 << Number))
{
return;
}
SlavePic.InServiceRegister |= 1 << Number;
if (!SlavePic.AutoEoi) SlavePic.InServiceRegister |= 1 << Number;
EmulatorInterrupt(SlavePic.IntOffset + Number);
}
}
VOID PitWriteCommand(BYTE Value)
{
BYTE Channel = Value >> 6;
BYTE Mode = (Value >> 1) & 0x07;
/* Set the access mode and reset flip-flop */
// TODO: Support latch command!
PitChannels[Channel].AccessMode = (Value >> 4) & 3;
PitChannels[Channel].FlipFlop = FALSE;
switch (Mode)
{
case 0:
case 4:
{
PitChannels[Channel].RateGenerator = FALSE;
break;
}
case 2:
case 3:
{
PitChannels[Channel].RateGenerator = TRUE;
break;
}
}
}
VOID PitWriteData(BYTE Channel, BYTE Value)
{
/* Use the flip-flop for access mode 3 */
if (PitChannels[Channel].AccessMode == 3)
{
PitChannels[Channel].AccessMode = PitChannels[Channel].FlipFlop ? 1 : 2;
PitChannels[Channel].FlipFlop = !PitChannels[Channel].FlipFlop;
}
switch (PitChannels[Channel].AccessMode)
{
case 1:
{
/* Low byte */
PitChannels[Channel].ReloadValue &= 0xFF00;
PitChannels[Channel].ReloadValue |= Value;
break;
}
case 2:
{
/* High byte */
PitChannels[Channel].ReloadValue &= 0x00FF;
PitChannels[Channel].ReloadValue |= Value << 8;
}
}
}
VOID PitInitialize()
{
HANDLE ThreadHandle;
/* Set up channel 0 */
PitChannels[0].ReloadValue = 0;
PitChannels[0].RateGenerator = TRUE;
PitChannels[0].Pulsed = FALSE;
PitChannels[0].AccessMode = 3;
PitChannels[0].FlipFlop = FALSE;
/* Create the PIT timer thread */
ThreadHandle = CreateThread(NULL, 0, PitThread, NULL, 0, NULL);
/* We don't need the handle */
CloseHandle(ThreadHandle);
}

4
subsystems/ntvdm/ntvdm.h
View file

@ -208,11 +208,15 @@ VOID DosInt20h(WORD CodeSegment);
VOID DosInt21h(WORD CodeSegment);
VOID DosBreakInterrupt();
VOID BiosVideoService();
VOID BiosHandleIrq(BYTE IrqNumber);
BYTE PicReadCommand(BYTE Port);
VOID PicWriteCommand(BYTE Port, BYTE Value);
BYTE PicReadData(BYTE Port);
VOID PicWriteData(BYTE Port, BYTE Value);
VOID PicInterruptRequest(BYTE Number);
VOID PitInitialize();
VOID PitWriteCommand(BYTE Value);
VOID PitWriteData(BYTE Channel, BYTE Value);
VOID EmulatorSetStack(WORD Segment, WORD Offset);
VOID EmulatorExecute(WORD Segment, WORD Offset);
VOID EmulatorInterrupt(BYTE Number);