GBA.Unity/Assets/emulator/DmaGba.cs

444 lines
14 KiB
C#

using static OptimeGBA.Bits;
using System;
namespace OptimeGBA
{
public enum DmaStartTimingGba
{
Immediately = 0,
VBlank = 1,
HBlank = 2,
Special = 3,
}
public sealed class DmaChannelGba
{
public uint DMASAD;
public uint DMADAD;
public uint DMACNT_L;
public uint DmaSource;
public uint DmaDest;
public uint DmaLength;
// DMACNT_H
public DmaDestAddrCtrl DestAddrCtrl;
public DmaSrcAddrCtrl SrcAddrCtrl;
public bool Repeat;
public bool TransferType;
public bool GamePakDRQ;
public DmaStartTimingGba StartTiming;
public bool FinishedIRQ;
public bool Enabled; // Don't directly set to false, use Disable()
public uint DMACNT_H;
public byte ReadHwio8(uint addr)
{
// DMASAD, DMADAD, and DMACNT_L are write-only
byte val = 0;
switch (addr)
{
case 0x0A: // DMACNT_H B0
case 0x0B: // DMACNT_H B1
val = GetByteIn(GetControl(), addr & 1);
break;
}
return val;
}
public void WriteHwio8(uint addr, byte val)
{
switch (addr)
{
case 0x00: // DMASAD B0
case 0x01: // DMASAD B1
case 0x02: // DMASAD B2
case 0x03: // DMASAD B3
DMASAD = SetByteIn(DMASAD, val, addr & 3);
break;
case 0x04: // DMADAD B0
case 0x05: // DMADAD B1
case 0x06: // DMADAD B2
case 0x07: // DMADAD B3
DMADAD = SetByteIn(DMADAD, val, addr & 3);
break;
case 0x08: // DMACNT_L B0
case 0x09: // DMACNT_L B1
DMACNT_L = SetByteIn(DMACNT_L, val, addr & 1);
break;
case 0x0A: // DMACNT_H B0
case 0x0B: // DMACNT_H B1
DMACNT_H = SetByteIn(DMACNT_H, val, addr & 1);
UpdateControl();
break;
}
}
public void UpdateControl()
{
DestAddrCtrl = (DmaDestAddrCtrl)BitRange(DMACNT_H, 5, 6);
SrcAddrCtrl = (DmaSrcAddrCtrl)BitRange(DMACNT_H, 7, 8);
Repeat = BitTest(DMACNT_H, 9);
TransferType = BitTest(DMACNT_H, 10);
GamePakDRQ = BitTest(DMACNT_H, 11);
StartTiming = (DmaStartTimingGba)BitRange(DMACNT_H, 12, 13);
FinishedIRQ = BitTest(DMACNT_H, 14);
if (BitTest(DMACNT_H, 15))
{
Enable();
}
else
{
Disable();
}
}
public uint GetControl()
{
uint val = 0;
val |= ((uint)DestAddrCtrl & 0b11) << 5;
val |= ((uint)SrcAddrCtrl & 0b11) << 7;
if (Repeat) val = BitSet(val, 9);
if (TransferType) val = BitSet(val, 10);
if (GamePakDRQ) val = BitSet(val, 11);
val |= ((uint)StartTiming & 0b11) << 12;
if (FinishedIRQ) val = BitSet(val, 14);
if (Enabled) val = BitSet(val, 15);
DMACNT_H = val;
return val;
}
public void Enable()
{
if (!Enabled)
{
DmaSource = DMASAD;
DmaDest = DMADAD;
DmaLength = DMACNT_L;
}
Enabled = true;
GetControl();
}
public void Disable()
{
Enabled = false;
GetControl();
}
}
public unsafe sealed class DmaGba
{
Gba Gba;
public DmaChannelGba[] Ch = new DmaChannelGba[4] {
new DmaChannelGba(),
new DmaChannelGba(),
new DmaChannelGba(),
new DmaChannelGba(),
};
static readonly uint[] DmaSourceMask = { 0x07FFFFFF, 0x0FFFFFFF, 0x0FFFFFFF, 0x0FFFFFFF };
static readonly uint[] DmaDestMask = { 0x07FFFFFF, 0x07FFFFFF, 0x07FFFFFF, 0x0FFFFFFFF };
public bool DmaLock;
public DmaGba(Gba gba)
{
Gba = gba;
}
public byte ReadHwio8(uint addr)
{
if (addr >= 0x40000B0 && addr <= 0x40000BB)
{
return Ch[0].ReadHwio8(addr - 0x40000B0);
}
else if (addr >= 0x40000BC && addr <= 0x40000C7)
{
return Ch[1].ReadHwio8(addr - 0x40000BC);
}
else if (addr >= 0x40000C8 && addr <= 0x40000D3)
{
return Ch[2].ReadHwio8(addr - 0x40000C8);
}
else if (addr >= 0x40000D4 && addr <= 0x40000DF)
{
return Ch[3].ReadHwio8(addr - 0x40000D4);
}
throw new Exception("This shouldn't happen.");
}
public void WriteHwio8(uint addr, byte val)
{
if (addr >= 0x40000B0 && addr <= 0x40000BB)
{
bool oldEnabled = Ch[0].Enabled;
Ch[0].WriteHwio8(addr - 0x40000B0, val);
if (!oldEnabled && Ch[0].Enabled) ExecuteImmediate(0);
return;
}
else if (addr >= 0x40000BC && addr <= 0x40000C7)
{
bool oldEnabled = Ch[1].Enabled;
Ch[1].WriteHwio8(addr - 0x40000BC, val);
if (!oldEnabled && Ch[1].Enabled) ExecuteImmediate(1);
return;
}
else if (addr >= 0x40000C8 && addr <= 0x40000D3)
{
bool oldEnabled = Ch[2].Enabled;
Ch[2].WriteHwio8(addr - 0x40000C8, val);
if (!oldEnabled && Ch[2].Enabled) ExecuteImmediate(2);
return;
}
else if (addr >= 0x40000D4 && addr <= 0x40000DF)
{
bool oldEnabled = Ch[3].Enabled;
Ch[3].WriteHwio8(addr - 0x40000D4, val);
if (!oldEnabled && Ch[3].Enabled) ExecuteImmediate(3);
return;
}
throw new Exception("This shouldn't happen.");
}
public void ExecuteDma(DmaChannelGba c, uint ci)
{
DmaLock = true;
// Least significant 28 (or 27????) bits
c.DmaSource &= DmaSourceMask[ci];
c.DmaDest &= DmaDestMask[ci];
if (ci == 3)
{
// DMA 3 is 16-bit length
c.DmaLength &= 0b1111111111111111;
// Value of zero is treated as maximum length
if (c.DmaLength == 0) c.DmaLength = 0x10000;
}
else
{
// DMA 0-2 are 14-bit length
c.DmaLength &= 0b11111111111111;
// Value of zero is treated as maximum length
if (c.DmaLength == 0) c.DmaLength = 0x4000;
}
// Console.WriteLine($"Starting DMA {ci}");
// Console.WriteLine($"SRC: {Util.HexN(srcAddr, 7)}");
// Console.WriteLine($"DEST: {Util.HexN(destAddr, 7)}");
// Console.WriteLine($"LENGTH: {Util.HexN(c.DmaLength, 4)}");
int destOffsPerUnit;
int sourceOffsPerUnit;
if (c.TransferType)
{
switch (c.DestAddrCtrl)
{
case DmaDestAddrCtrl.Increment: destOffsPerUnit = +4; break;
case DmaDestAddrCtrl.Decrement: destOffsPerUnit = -4; break;
case DmaDestAddrCtrl.IncrementReload: destOffsPerUnit = +4; break;
default: destOffsPerUnit = 0; break;
}
switch (c.SrcAddrCtrl)
{
case DmaSrcAddrCtrl.Increment: sourceOffsPerUnit = +4; break;
case DmaSrcAddrCtrl.Decrement: sourceOffsPerUnit = -4; break;
default: sourceOffsPerUnit = 0; break;
}
}
else
{
switch (c.DestAddrCtrl)
{
case DmaDestAddrCtrl.Increment: destOffsPerUnit = +2; break;
case DmaDestAddrCtrl.Decrement: destOffsPerUnit = -2; break;
case DmaDestAddrCtrl.IncrementReload: destOffsPerUnit = +2; break;
default: destOffsPerUnit = 0; break;
}
switch (c.SrcAddrCtrl)
{
case DmaSrcAddrCtrl.Increment: sourceOffsPerUnit = +2; break;
case DmaSrcAddrCtrl.Decrement: sourceOffsPerUnit = -2; break;
default: sourceOffsPerUnit = 0; break;
}
}
uint origLength = c.DmaLength;
if (c.TransferType)
{
for (; c.DmaLength > 0; c.DmaLength--)
{
Gba.Mem.Write32(c.DmaDest & ~3u, Gba.Mem.Read32(c.DmaSource & ~3u));
Gba.Tick(Gba.Cpu.Timing32[(c.DmaSource >> 24) & 0xF]);
Gba.Tick(Gba.Cpu.Timing32[(c.DmaDest >> 24) & 0xF]);
c.DmaDest = (uint)(long)(destOffsPerUnit + c.DmaDest);
c.DmaSource = (uint)(long)(sourceOffsPerUnit + c.DmaSource);
}
}
else
{
for (; c.DmaLength > 0; c.DmaLength--)
{
Gba.Mem.Write16(c.DmaDest & ~1u, Gba.Mem.Read16(c.DmaSource & ~1u));
Gba.Tick(Gba.Cpu.Timing8And16[(c.DmaSource >> 24) & 0xF]);
Gba.Tick(Gba.Cpu.Timing8And16[(c.DmaDest >> 24) & 0xF]);
c.DmaDest = (uint)(long)(destOffsPerUnit + c.DmaDest);
c.DmaSource = (uint)(long)(sourceOffsPerUnit + c.DmaSource);
}
}
if (c.DestAddrCtrl == DmaDestAddrCtrl.IncrementReload)
{
c.DmaLength = origLength;
if (c.Repeat)
{
c.DmaDest = c.DMADAD;
}
}
if (c.FinishedIRQ)
{
Gba.HwControl.FlagInterrupt((uint)InterruptGba.Dma0 + ci);
}
DmaLock = false;
}
public void ExecuteSoundDma(DmaChannelGba c, uint ci)
{
DmaLock = true;
// Least significant 28 (or 27????) bits
uint srcAddr = c.DmaSource & 0b1111111111111111111111111111;
uint destAddr = c.DmaDest & 0b111111111111111111111111111;
// 4 units of 32bits (16 bytes) are transferred to FIFO_A or FIFO_B
for (uint i = 0; i < 4; i++)
{
uint val = Gba.Mem.Read32(srcAddr + 0);
if (destAddr == 0x40000A0)
{
Gba.GbaAudio.A.Insert((byte)val);
Gba.GbaAudio.A.Insert((byte)(val >>= 8));
Gba.GbaAudio.A.Insert((byte)(val >>= 8));
Gba.GbaAudio.A.Insert((byte)(val >>= 8));
}
else if (destAddr == 0x40000A4)
{
Gba.GbaAudio.B.Insert((byte)val);
Gba.GbaAudio.B.Insert((byte)(val >>= 8));
Gba.GbaAudio.B.Insert((byte)(val >>= 8));
Gba.GbaAudio.B.Insert((byte)(val >>= 8));
}
else
{
Gba.Mem.Write8(destAddr + 0, (byte)val);
Gba.Mem.Write8(destAddr + 1, (byte)(val >>= 8));
Gba.Mem.Write8(destAddr + 2, (byte)(val >>= 8));
Gba.Mem.Write8(destAddr + 3, (byte)(val >>= 8));
}
switch (c.SrcAddrCtrl)
{
case DmaSrcAddrCtrl.Increment: srcAddr += 4; break;
case DmaSrcAddrCtrl.Decrement: srcAddr -= 4; break;
case DmaSrcAddrCtrl.Fixed: break;
}
// Applying proper timing to sound DMAs causes crackling in certain games including PMD.
// This only happens with scheduled timers, which leads me to believe the real problem is in there.
// PROBLEM SOLVED.... my timers were 1 cycle too slow to reload
Gba.Cpu.InstructionCycles += (Gba.Cpu.Timing32[(c.DmaSource >> 24) & 0xF]);
Gba.Cpu.InstructionCycles += (Gba.Cpu.Timing32[(c.DmaDest >> 24) & 0xF]);
}
c.DmaSource = srcAddr;
if (c.FinishedIRQ)
{
Gba.HwControl.FlagInterrupt((uint)InterruptGba.Dma0 + ci);
}
DmaLock = false;
}
public void ExecuteImmediate(uint ci)
{
DmaChannelGba c = Ch[ci];
if (c.Enabled && c.StartTiming == DmaStartTimingGba.Immediately)
{
c.Disable();
ExecuteDma(c, ci);
}
}
public void RepeatFifoA()
{
if (!DmaLock)
{
if (Ch[1].StartTiming == DmaStartTimingGba.Special)
{
ExecuteSoundDma(Ch[1], 1);
}
}
}
public void RepeatFifoB()
{
if (!DmaLock)
{
if (Ch[2].StartTiming == DmaStartTimingGba.Special)
{
ExecuteSoundDma(Ch[2], 2);
}
}
}
public void RepeatHblank()
{
if (!DmaLock)
{
for (uint ci = 0; ci < 4; ci++)
{
DmaChannelGba c = Ch[ci];
if (c.StartTiming == DmaStartTimingGba.HBlank)
{
c.DmaLength = c.DMACNT_L;
ExecuteDma(c, ci);
}
}
}
}
public void RepeatVblank()
{
if (!DmaLock)
{
for (uint ci = 0; ci < 4; ci++)
{
DmaChannelGba c = Ch[ci];
if (c.StartTiming == DmaStartTimingGba.VBlank)
{
c.DmaLength = c.DMACNT_L;
ExecuteDma(c, ci);
}
}
}
}
}
}