sGBA
Released
●1
Emulator/GbaBios.cs
namespace sGBA;
public partial class GbaBios
{
public Gba Gba { get; }
public bool HleActive;
public int BiosStall;
public GbaBios( Gba gba )
{
Gba = gba;
}
public bool HandleSwi( uint comment )
{
switch ( comment )
{
case 0xF0:
Gba.Cpu.Registers[11] = (uint)BiosStall;
return true;
case 0xFA:
Gba.Memory.FlushAgbPrint();
return true;
}
HleActive = true;
BiosStall = 0;
bool useStall = false;
switch ( comment )
{
case 0x00: // SoftReset
HleActive = false;
return false;
case 0x01: RegisterRamReset(); break;
case 0x02: // Halt
HleActive = false;
return false;
case 0x03: Stop(); break;
case 0x04: // IntrWait
case 0x05: // VBlankIntrWait
HleActive = false;
return false;
case 0x06:
useStall = true;
Div();
break;
case 0x07:
useStall = true;
DivArm();
break;
case 0x08:
useStall = true;
Sqrt();
break;
case 0x09:
useStall = true;
ArcTan();
break;
case 0x0A:
useStall = true;
ArcTan2();
break;
case 0x0B: // CpuSet
case 0x0C: // CpuFastSet
if ( (Gba.Cpu.Registers[0] >> 24) < 2 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Cannot CpuSet from BIOS" );
break;
}
uint alignmentMask = (Gba.Cpu.Registers[2] & (1u << 26)) != 0 ? 3u : 1u;
if ( (Gba.Cpu.Registers[0] & alignmentMask) != 0 )
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Misaligned CpuSet source" );
if ( (Gba.Cpu.Registers[1] & alignmentMask) != 0 )
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Misaligned CpuSet destination" );
HleActive = false;
return false;
case 0x0D: GetBiosChecksum(); break;
case 0x0E: BgAffineSet(); break;
case 0x0F: ObjAffineSet(); break;
case 0x10:
if ( Gba.Cpu.Registers[0] < 0x02000000 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad BitUnPack source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad BitUnPack destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
BitUnPack();
break;
}
break;
case 0x11:
if ( (Gba.Cpu.Registers[0] & 0x0E000000) == 0 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad LZ77 source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad LZ77 destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
useStall = true;
LZ77UnCompWram();
break;
}
break;
case 0x12:
if ( (Gba.Cpu.Registers[0] & 0x0E000000) == 0 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad LZ77 source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad LZ77 destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
useStall = true;
LZ77UnCompVram();
break;
}
break;
case 0x13:
if ( (Gba.Cpu.Registers[0] & 0x0E000000) == 0 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad Huffman source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad Huffman destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
HuffmanUnComp();
break;
}
break;
case 0x14:
if ( (Gba.Cpu.Registers[0] & 0x0E000000) == 0 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad RL source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad RL destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
RLUnCompWram();
break;
}
break;
case 0x15:
if ( (Gba.Cpu.Registers[0] & 0x0E000000) == 0 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad RL source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad RL destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
RLUnCompVram();
break;
}
break;
case 0x16:
if ( (Gba.Cpu.Registers[0] & 0x0E000000) == 0 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad UnFilter source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad UnFilter destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
Diff8BitUnFilterWram();
break;
}
break;
case 0x17:
if ( (Gba.Cpu.Registers[0] & 0x0E000000) == 0 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad UnFilter source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad UnFilter destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
Diff8BitUnFilterVram();
break;
}
break;
case 0x18:
if ( (Gba.Cpu.Registers[0] & 0x0E000000) == 0 )
{
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad UnFilter source" );
break;
}
switch ( Gba.Cpu.Registers[1] >> 24 )
{
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.GameError, "Bad UnFilter destination" );
goto case 0x2;
case 0x2:
case 0x3:
case 0x6:
Diff16BitUnFilter();
break;
}
break;
case 0x19:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.Stub, "Stub software interrupt: SoundBias (19)" );
break;
case 0x1F: MidiKey2Freq(); break;
case 0x2A: // SoundDriverGetJumpList
HleActive = false;
return false;
default:
GbaLog.Write( LogCategory.GBABIOS, LogLevel.Stub, "Stub software interrupt: {0:X2}", comment );
break;
}
if ( useStall && BiosStall >= 18 )
{
BiosStall -= 18;
Gba.Cpu.Cycles += BiosStall & 3;
BiosStall &= ~3;
HleActive = false;
return false;
}
if ( useStall )
{
Gba.Cpu.Cycles += BiosStall;
}
HleActive = false;
int region = (int)((Gba.Cpu.Gprs[15] >> 24) & 0xF);
Gba.Cpu.Cycles += 45 + Gba.Memory.WaitstatesNonseq16[region];
if ( Gba.Cpu.ThumbMode )
Gba.Cpu.Cycles += Gba.Memory.WaitstatesNonseq16[region] + Gba.Memory.WaitstatesSeq16[region];
else
Gba.Cpu.Cycles += Gba.Memory.WaitstatesNonseq32[region] + Gba.Memory.WaitstatesSeq32[region];
Gba.Memory.BiosPrefetch = 0xE3A02004;
return true;
}
private void GetBiosChecksum()
{
Gba.Cpu.Registers[0] = 0xBAAE187F;
Gba.Cpu.Registers[1] = 1;
Gba.Cpu.Registers[3] = 0x4000;
}
private void RegisterRamReset()
{
uint flags = Gba.Cpu.Registers[0];
var io = Gba.Io;
io.Write16( 0x000, 0x0080 );
if ( (flags & 0x01) != 0 )
Gba.Memory.Wram.AsSpan( 0, 0x40000 ).Clear();
if ( (flags & 0x02) != 0 )
Gba.Memory.Iwram.AsSpan( 0, 0x7E00 ).Clear();
if ( (flags & 0x04) != 0 )
Array.Clear( Gba.Memory.PaletteRam );
if ( (flags & 0x08) != 0 )
Gba.Memory.Vram.AsSpan( 0, 0x18000 ).Clear();
if ( (flags & 0x10) != 0 )
Array.Clear( Gba.Memory.Oam );
if ( (flags & 0x20) != 0 )
{
io.Write16( 0x128, 0 );
io.Write16( 0x134, 0x8000 );
io.Write16( 0x120, 0 );
io.Write16( 0x140, 0 );
io.Write16( 0x150, 0 );
io.Write16( 0x152, 0 );
io.Write16( 0x154, 0 );
io.Write16( 0x156, 0 );
}
if ( (flags & 0x40) != 0 )
{
var apu = Gba.Audio;
apu.WriteRegister( 0x60, 0 );
apu.WriteRegister( 0x62, 0 );
apu.WriteRegister( 0x64, 0 );
apu.WriteRegister( 0x68, 0 );
apu.WriteRegister( 0x6C, 0 );
apu.WriteRegister( 0x70, 0 );
apu.WriteRegister( 0x72, 0 );
apu.WriteRegister( 0x74, 0 );
apu.WriteRegister( 0x78, 0 );
apu.WriteRegister( 0x7C, 0 );
apu.WriteRegister( 0x80, 0 );
apu.WriteRegister( 0x82, 0 );
apu.WriteRegister( 0x84, 0 );
apu.WriteRegister( 0x088, 0x0200 );
Array.Clear( apu.WaveRam );
}
if ( (flags & 0x80) != 0 )
{
io.Write16( 0x004, 0 );
io.Write16( 0x006, 0 );
io.Write16( 0x008, 0 );
io.Write16( 0x00A, 0 );
io.Write16( 0x00C, 0 );
io.Write16( 0x00E, 0 );
io.Write16( 0x010, 0 );
io.Write16( 0x012, 0 );
io.Write16( 0x014, 0 );
io.Write16( 0x016, 0 );
io.Write16( 0x018, 0 );
io.Write16( 0x01A, 0 );
io.Write16( 0x01C, 0 );
io.Write16( 0x01E, 0 );
io.Write16( 0x020, 0x0100 );
io.Write16( 0x022, 0 );
io.Write16( 0x024, 0 );
io.Write16( 0x026, 0x0100 );
io.Write16( 0x028, 0 );
io.Write16( 0x02A, 0 );
io.Write16( 0x02C, 0 );
io.Write16( 0x02E, 0 );
io.Write16( 0x030, 0x0100 );
io.Write16( 0x032, 0 );
io.Write16( 0x034, 0 );
io.Write16( 0x036, 0x0100 );
io.Write16( 0x038, 0 );
io.Write16( 0x03A, 0 );
io.Write16( 0x03C, 0 );
io.Write16( 0x03E, 0 );
io.Write16( 0x040, 0 );
io.Write16( 0x042, 0 );
io.Write16( 0x044, 0 );
io.Write16( 0x046, 0 );
io.Write16( 0x048, 0 );
io.Write16( 0x04A, 0 );
io.Write16( 0x04C, 0 );
io.Write16( 0x050, 0 );
io.Write16( 0x052, 0 );
io.Write16( 0x054, 0 );
for ( uint ch = 0; ch < 4; ch++ )
{
uint b = 0x0B0 + ch * 12;
io.Write16( b, 0 );
io.Write16( b + 2, 0 );
io.Write16( b + 4, 0 );
io.Write16( b + 6, 0 );
io.Write16( b + 8, 0 );
io.Write16( b + 10, 0 );
}
for ( uint t = 0; t < 4; t++ )
{
io.Write16( 0x100 + t * 4, 0 );
io.Write16( 0x102 + t * 4, 0 );
}
io.Write16( 0x200, 0 );
io.Write16( 0x202, 0xFFFF );
io.Write16( 0x204, 0 );
io.Write16( 0x208, 0 );
}
}
private void Stop()
{
Gba.Cpu.Halted = true;
}
}