public static void Return(IWriteonlyRegister <ushort> pc, IStack stack)
{
var low = stack.Pop();
var high = stack.Pop();
Load(pc, BitUtils.Combine(low, high));
}
public static void Pop(IWriteonlyRegister <ushort> target, IStack stack)
{
var low = stack.Pop();
var high = stack.Pop();
target.Value = BitUtils.Combine(low, high);
}
public void Combine(byte high, byte low, ushort expected)
{
Assert.AreEqual(expected, BitUtils.Combine(low, high));
}
/// <summary>
/// Executes the next instruction and modifies the passed machine state accordingly.
/// </summary>
/// <param name="m">Machine state before execution.</param>
/// <returns>Elapsed clock cycles.</returns>
public static int ExecuteNextInstruction(IMachineState m)
{
var opcode = NextInstructionByte(m);
switch (opcode)
{
#region NOP
case 0x00:
return(4);
#endregion
#region LD reg, reg'
case 0x40:
case 0x41:
case 0x42:
case 0x43:
case 0x44:
case 0x45:
case 0x47:
case 0x48:
case 0x49:
case 0x4A:
case 0x4B:
case 0x4C:
case 0x4D:
case 0x4F:
case 0x50:
case 0x51:
case 0x52:
case 0x53:
case 0x54:
case 0x55:
case 0x57:
case 0x58:
case 0x59:
case 0x5A:
case 0x5B:
case 0x5C:
case 0x5D:
case 0x5F:
case 0x60:
case 0x61:
case 0x62:
case 0x63:
case 0x64:
case 0x65:
case 0x67:
case 0x68:
case 0x69:
case 0x6A:
case 0x6B:
case 0x6C:
case 0x6D:
case 0x6F:
case 0x7F:
case 0x78:
case 0x79:
case 0x7A:
case 0x7B:
case 0x7C:
case 0x7D:
{
var regTarget = m.Registers.GetRegisterById((opcode & 0x38) >> 3);
var regSource = m.Registers.GetRegisterById(opcode & 0x07);
Instructions.Load(regTarget, regSource.Value);
return(4);
}
#endregion
#region LD reg, imm
case 0x06:
case 0x0E:
case 0x16:
case 0x1E:
case 0x26:
case 0x2E:
case 0x3E:
{
var reg = m.Registers.GetRegisterById((opcode & 0x38) >> 3);
Instructions.Load(reg, NextInstructionByte(m));
return(8);
}
#endregion
#region LD reg, (HL)
case 0x7E:
case 0x46:
case 0x4E:
case 0x56:
case 0x5E:
case 0x66:
case 0x6E:
{
var regTarget = m.Registers.GetRegisterById((opcode & 0x38) >> 3);
var value = m.Memory[m.Registers.HL.Value];
Instructions.Load(regTarget, value);
return(8);
}
#endregion
#region LD (HL), reg
case 0x70:
case 0x71:
case 0x72:
case 0x73:
case 0x74:
case 0x75:
case 0x77:
{
var target = new MemoryLocation(m.Memory, m.Registers.HL.Value);
var regSource = m.Registers.GetRegisterById(opcode & 0x07);
Instructions.Load(target, regSource.Value);
return(8);
}
#endregion
#region LD (HL), imm
case 0x36:
{
var target = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Load(target, NextInstructionByte(m));
return(12);
}
#endregion
#region LD A, (BC)
case 0x0A:
{
var source = new MemoryLocation(m.Memory, m.Registers.BC.Value);
Instructions.Load(m.Registers.A, source.Value);
return(8);
}
#endregion
#region LD A, (DE)
case 0x1A:
{
var source = new MemoryLocation(m.Memory, m.Registers.DE.Value);
Instructions.Load(m.Registers.A, source.Value);
return(8);
}
#endregion
#region LD A, (C)
case 0xF2:
{
var source = new MemoryLocation(m.Memory, 0xFF00 + m.Registers.C.Value);
Instructions.Load(m.Registers.A, source.Value);
return(8);
}
#endregion
#region LD (C), A
case 0xE2:
{
var target = new MemoryLocation(m.Memory, 0xFF00 + m.Registers.C.Value);
Instructions.Load(target, m.Registers.A.Value);
return(8);
}
#endregion
#region LD A, (n)
case 0xF0:
{
var source = new MemoryLocation(m.Memory, 0xFF00 + NextInstructionByte(m));
Instructions.Load(m.Registers.A, source.Value);
return(12);
}
#endregion
#region LD (n), A
case 0xE0:
{
var target = new MemoryLocation(m.Memory, 0xFF00 + NextInstructionByte(m));
Instructions.Load(target, m.Registers.A.Value);
return(12);
}
#endregion
#region LD A, (nn)
case 0xFA:
{
var low = NextInstructionByte(m);
var high = NextInstructionByte(m);
var source = new MemoryLocation(m.Memory, BitUtils.Combine(low, high));
Instructions.Load(m.Registers.A, source.Value);
return(16);
}
#endregion
#region LD (nn), A
case 0xEA:
{
var low = NextInstructionByte(m);
var high = NextInstructionByte(m);
var target = new MemoryLocation(m.Memory, BitUtils.Combine(low, high));
Instructions.Load(target, m.Registers.A.Value);
return(16);
}
#endregion
#region LD A, (HL+)
case 0x2A:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Load(m.Registers.A, source.Value);
m.Registers.HL.Value++;
return(8);
}
#endregion
#region LD A, (HL-)
case 0x3A:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Load(m.Registers.A, source.Value);
m.Registers.HL.Value--;
return(8);
}
#endregion
#region LD (BC), A
case 0x02:
{
var target = new MemoryLocation(m.Memory, m.Registers.BC.Value);
Instructions.Load(target, m.Registers.A.Value);
return(8);
}
#endregion
#region LD (DE), A
case 0x12:
{
var target = new MemoryLocation(m.Memory, m.Registers.DE.Value);
Instructions.Load(target, m.Registers.A.Value);
return(8);
}
#endregion
#region LD (HL+), A
case 0x22:
{
var target = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Load(target, m.Registers.A.Value);
m.Registers.HL.Value++;
return(8);
}
#endregion
#region LD (HL-), A
case 0x32:
{
var target = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Load(target, m.Registers.A.Value);
m.Registers.HL.Value--;
return(8);
}
#endregion
#region LD reg16, imm16
case 0x01:
case 0x11:
case 0x21:
case 0x31:
{
var low = NextInstructionByte(m);
var high = NextInstructionByte(m);
var target = m.Registers.GetSpecialRegisterPairById((opcode & 0x30) >> 4);
Instructions.Load(target, BitUtils.Combine(low, high));
return(12);
}
#endregion
#region LD SP, HL
case 0xF9:
{
Instructions.Load(m.Registers.SP, m.Registers.HL.Value);
return(8);
}
#endregion
#region PUSH qq
case 0xF5:
case 0xC5:
case 0xD5:
case 0xE5:
{
var reg = m.Registers.GetGeneralRegisterPairById((opcode & 0x30) >> 4);
Instructions.Push(m.Stack, reg.Value);
return(16);
}
#endregion
#region POP qq
case 0xF1:
case 0xC1:
case 0xD1:
case 0xE1:
{
var reg = m.Registers.GetGeneralRegisterPairById((opcode & 0x30) >> 4);
Instructions.Pop(reg, m.Stack);
return(12);
}
#endregion
#region LDHL SP, e
case 0xF8:
{
var e = (sbyte)NextInstructionByte(m);
Instructions.LoadWithSignedOffset(m.Registers.HL, m.Registers.SP, e, m.Registers.Flags);
return(12);
}
#endregion
#region LD (nn), SP
case 0x08:
{
var low = NextInstructionByte(m);
var high = NextInstructionByte(m);
var targetLow = new MemoryLocation(m.Memory, BitUtils.Combine(low, high));
var targetHigh = new MemoryLocation(m.Memory, BitUtils.Combine(low, high) + 1);
Instructions.Load(targetLow, m.Registers.SP.Value.GetLow());
Instructions.Load(targetHigh, m.Registers.SP.Value.GetHigh());
return(20);
}
#endregion
#region ADD A, reg
case 0x87:
case 0x80:
case 0x81:
case 0x82:
case 0x83:
case 0x84:
case 0x85:
{
var regSource = m.Registers.GetRegisterById(opcode & 0x7);
Instructions.Add(m.Registers.A, regSource.Value, m.Registers.Flags);
return(4);
}
#endregion
#region ADD A, (HL)
case 0x86:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Add(m.Registers.A, source.Value, m.Registers.Flags);
return(8);
}
#endregion
#region ADD A, imm
case 0xC6:
{
var imm = NextInstructionByte(m);
Instructions.Add(m.Registers.A, imm, m.Registers.Flags);
return(8);
}
#endregion
#region ADC A, reg
case 0x8F:
case 0x88:
case 0x89:
case 0x8A:
case 0x8B:
case 0x8C:
case 0x8D:
{
var regSource = m.Registers.GetRegisterById(opcode & 0x7);
Instructions.AddPlusCarry(m.Registers.A, regSource.Value, m.Registers.Flags);
return(4);
}
#endregion
#region ADC A, (HL)
case 0x8E:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.AddPlusCarry(m.Registers.A, source.Value, m.Registers.Flags);
return(8);
}
#endregion
#region ADC A, imm
case 0xCE:
{
var imm = NextInstructionByte(m);
Instructions.AddPlusCarry(m.Registers.A, imm, m.Registers.Flags);
return(8);
}
#endregion
#region SUB A, reg
case 0x97:
case 0x90:
case 0x91:
case 0x92:
case 0x93:
case 0x94:
case 0x95:
{
var regSource = m.Registers.GetRegisterById(opcode & 0x7);
Instructions.Subtract(m.Registers.A, regSource.Value, m.Registers.Flags);
return(4);
}
#endregion
#region SUB A, (HL)
case 0x96:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Subtract(m.Registers.A, source.Value, m.Registers.Flags);
return(8);
}
#endregion
#region SUB A, imm
case 0xD6:
{
var imm = NextInstructionByte(m);
Instructions.Subtract(m.Registers.A, imm, m.Registers.Flags);
return(8);
}
#endregion
#region SBC A, reg
case 0x9F:
case 0x98:
case 0x99:
case 0x9A:
case 0x9B:
case 0x9C:
case 0x9D:
{
var regSource = m.Registers.GetRegisterById(opcode & 0x7);
Instructions.SubtractMinusCarry(m.Registers.A, regSource.Value, m.Registers.Flags);
return(4);
}
#endregion
#region SBC A, (HL)
case 0x9E:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.SubtractMinusCarry(m.Registers.A, source.Value, m.Registers.Flags);
return(8);
}
#endregion
#region SBC A, imm
case 0xDE:
{
var imm = NextInstructionByte(m);
Instructions.SubtractMinusCarry(m.Registers.A, imm, m.Registers.Flags);
return(8);
}
#endregion
#region AND A, reg
case 0xA7:
case 0xA0:
case 0xA1:
case 0xA2:
case 0xA3:
case 0xA4:
case 0xA5:
{
var regSource = m.Registers.GetRegisterById(opcode & 0x7);
Instructions.And(m.Registers.A, regSource.Value, m.Registers.Flags);
return(4);
}
#endregion
#region AND A, (HL)
case 0xA6:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.And(m.Registers.A, source.Value, m.Registers.Flags);
return(8);
}
#endregion
#region AND A, imm
case 0xE6:
{
var imm = NextInstructionByte(m);
Instructions.And(m.Registers.A, imm, m.Registers.Flags);
return(8);
}
#endregion
#region OR A, reg
case 0xB7:
case 0xB0:
case 0xB1:
case 0xB2:
case 0xB3:
case 0xB4:
case 0xB5:
{
var regSource = m.Registers.GetRegisterById(opcode & 0x7);
Instructions.Or(m.Registers.A, regSource.Value, m.Registers.Flags);
return(4);
}
#endregion
#region OR A, (HL)
case 0xB6:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Or(m.Registers.A, source.Value, m.Registers.Flags);
return(8);
}
#endregion
#region OR A, imm
case 0xF6:
{
var imm = NextInstructionByte(m);
Instructions.Or(m.Registers.A, imm, m.Registers.Flags);
return(8);
}
#endregion
#region XOR A, reg
case 0xAF:
case 0xA8:
case 0xA9:
case 0xAA:
case 0xAB:
case 0xAC:
case 0xAD:
{
var regSource = m.Registers.GetRegisterById(opcode & 0x7);
Instructions.Xor(m.Registers.A, regSource.Value, m.Registers.Flags);
return(4);
}
#endregion
#region XOR A, (HL)
case 0xAE:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Xor(m.Registers.A, source.Value, m.Registers.Flags);
return(8);
}
#endregion
#region XOR A, imm
case 0xEE:
{
var imm = NextInstructionByte(m);
Instructions.Xor(m.Registers.A, imm, m.Registers.Flags);
return(8);
}
#endregion
#region CP A, reg
case 0xBF:
case 0xB8:
case 0xB9:
case 0xBA:
case 0xBB:
case 0xBC:
case 0xBD:
{
var regSource = m.Registers.GetRegisterById(opcode & 0x7);
Instructions.Compare(m.Registers.A, regSource.Value, m.Registers.Flags);
return(4);
}
#endregion
#region CP A, (HL)
case 0xBE:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Compare(m.Registers.A, source.Value, m.Registers.Flags);
return(8);
}
#endregion
#region CP A, imm
case 0xFE:
{
var imm = NextInstructionByte(m);
Instructions.Compare(m.Registers.A, imm, m.Registers.Flags);
return(8);
}
#endregion
#region INC reg
case 0x3C:
case 0x04:
case 0x0C:
case 0x14:
case 0x1C:
case 0x24:
case 0x2C:
{
var reg = m.Registers.GetRegisterById((opcode & 0x38) >> 3);
Instructions.Increment(reg, m.Registers.Flags);
return(4);
}
#endregion
#region INC (HL)
case 0x34:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Increment(source, m.Registers.Flags);
return(8);
}
#endregion
#region DEC reg
case 0x3D:
case 0x05:
case 0x0D:
case 0x15:
case 0x1D:
case 0x25:
case 0x2D:
{
var reg = m.Registers.GetRegisterById((opcode & 0x38) >> 3);
Instructions.Decrement(reg, m.Registers.Flags);
return(4);
}
#endregion
#region DEC (HL)
case 0x35:
{
var source = new MemoryLocation(m.Memory, m.Registers.HL.Value);
Instructions.Decrement(source, m.Registers.Flags);
return(8);
}
#endregion
#region ADD HL, reg16
case 0x09:
case 0x19:
case 0x29:
case 0x39:
{
var regSource = m.Registers.GetSpecialRegisterPairById((opcode & 0x30) >> 4);
Instructions.Add(m.Registers.HL, regSource.Value, m.Registers.Flags);
return(8);
}
#endregion
#region ADD SP, e
case 0xE8:
{
var reg = m.Registers.SP;
var e = (sbyte)NextInstructionByte(m);
Instructions.LoadWithSignedOffset(reg, reg, e, m.Registers.Flags);
return(16);
}
#endregion
#region INC reg16
case 0x03:
case 0x13:
case 0x23:
case 0x33:
{
var regSource = m.Registers.GetSpecialRegisterPairById((opcode & 0x30) >> 4);
Instructions.Increment(regSource);
return(8);
}
#endregion
#region DEC reg16
case 0x0B:
case 0x1B:
case 0x2B:
case 0x3B:
{
var regSource = m.Registers.GetSpecialRegisterPairById((opcode & 0x30) >> 4);
Instructions.Decrement(regSource);
return(8);
}
#endregion
// TODO re-check if these pairs are flipped, looks weird
#region RLCA
case 0x07:
{
Instructions.RotateLeftA(m.Registers.A, m.Registers.Flags);
return(4);
}
#endregion
#region RLA
case 0x17:
{
Instructions.RotateLeftThroughCarryA(m.Registers.A, m.Registers.Flags);
return(4);
}
#endregion
#region RRCA
case 0x0F:
{
Instructions.RotateRightA(m.Registers.A, m.Registers.Flags);
return(4);
}
#endregion
#region RRA
case 0x1F:
{
Instructions.RotateRightThroughCarryA(m.Registers.A, m.Registers.Flags);
return(4);
}
#endregion
case 0xCB:
{
return(ExecuteCB(m));
}
// TODO timing correct?
#region JP imm16
case 0xC3:
{
var low = NextInstructionByte(m);
var high = NextInstructionByte(m);
Instructions.Load(m.Registers.PC, BitUtils.Combine(low, high));
return(12);
}
#endregion
// TODO: timing correct?
#region JP cc, imm16
case 0xC2:
case 0xCA:
case 0xD2:
case 0xDA:
{
var low = NextInstructionByte(m);
var high = NextInstructionByte(m);
var condition = (JumpCondition)((opcode & 0x18) >> 3);
Instructions.ConditionalJump(m.Registers.PC, BitUtils.Combine(low, high),
condition, m.Registers.Flags);
return(12);
}
#endregion
// TODO re-check jump offset (should be correct though)
// TODO timing
#region JR e
case 0x18:
{
var offset = (sbyte)NextInstructionByte(m);
Instructions.JumpByOffset(m.Registers.PC, offset);
return(8);
}
#endregion
// TODO: timing?
#region JR cc, e
case 0x20:
case 0x28:
case 0x30:
case 0x38:
{
var condition = (JumpCondition)((opcode & 0x18) >> 3);
var offset = (sbyte)NextInstructionByte(m);
Instructions.ConditionalJumpByOffset(m.Registers.PC, offset,
condition, m.Registers.Flags);
return(8);
}
#endregion
#region JP (HL)
case 0xE9:
{
// This doesn't use the memory location pointed to by HL, but the value of HL itself!
Instructions.Load(m.Registers.PC, m.Registers.HL.Value);
return(4);
}
#endregion
#region CALL imm16
case 0xCD:
{
var low = NextInstructionByte(m);
var high = NextInstructionByte(m);
Instructions.Call(m.Registers.PC, BitUtils.Combine(low, high), m.Stack);
return(24);
}
#endregion
// TODO: timing!
#region CALL cc, imm16
case 0xC4:
case 0xCC:
case 0xD4:
case 0xDC:
{
var low = NextInstructionByte(m);
var high = NextInstructionByte(m);
var condition = (JumpCondition)((opcode & 0x18) >> 3);
Instructions.ConditionalCall(m.Registers.PC, BitUtils.Combine(low, high), m.Stack,
condition, m.Registers.Flags);
return(24);
}
#endregion
// TODO timing, manual says 16 cycles?
#region RET
case 0xC9:
{
Instructions.Return(m.Registers.PC, m.Stack);
return(8);
}
#endregion
// TODO timing, manual says 16 cycles?
#region RETI
case 0xD9:
{
Instructions.Return(m.Registers.PC, m.Stack);
m.InterruptMasterEnable = true; // "returned to its pre-interrupt status"?
return(8);
}
#endregion
// TODO: timing
#region RET cc
case 0xC0:
case 0xC8:
case 0xD0:
case 0xD8:
{
var condition = (JumpCondition)((opcode & 0x18) >> 3);
Instructions.ConditionalReturn(m.Registers.PC, m.Stack, condition, m.Registers.Flags);
return(8);
}
#endregion
// TODO timing, manual says 16 cycles?
#region RST t
case 0xC7:
case 0xCF:
case 0xD7:
case 0xDF:
case 0xE7:
case 0xEF:
case 0xF7:
case 0xFF:
{
var restartOffset = (byte)((opcode & 0b0011_1000) >> 3);
Instructions.Restart(m.Registers.PC, restartOffset, m.Stack);
return(16);
}
#endregion
#region DAA
case 0x27:
{
Instructions.DecimalAdjust(m.Registers.A, m.Registers.Flags);
return(4);
}
#endregion
#region CPL
case 0x2F:
{
Instructions.Complement(m.Registers.A, m.Registers.Flags);
return(4);
}
#endregion
#region CCF
case 0x3F:
{
Instructions.ComplementCarryFlag(m.Registers.Flags);
return(4);
}
#endregion
#region SCF
case 0x37:
{
Instructions.SetCarryFlag(m.Registers.Flags);
return(4);
}
#endregion
#region DI
case 0xF3:
{
m.InterruptMasterEnable = false;
return(4);
}
#endregion
#region EI
case 0xFB:
{
m.InterruptMasterEnable = true;
return(4);
}
#endregion
#region HALT
case 0x76:
{
m.Halted = true;
return(4);
}
#endregion
#region STOP
case 0x10:
{
m.Stopped = true;
return(4);
}
#endregion
default:
throw new InvalidOperationException("Invalid opcode.");
}
}
// TODO: Case statement is the same as in Cpu. Unify them somehow to make it
// less ugly.
public static Instruction DisassembleInstruction(IEnumerator <byte> lookahead)
{
var count = 0;
Func <byte> next = () =>
{
lookahead.MoveNext();
count++;
return(lookahead.Current);
};
var opcode = next();
switch (opcode)
{
#region NOP
case 0x00:
return(new Instruction("NOP", count));
#endregion
#region LD reg, reg'
case 0x40:
case 0x41:
case 0x42:
case 0x43:
case 0x44:
case 0x45:
case 0x47:
case 0x48:
case 0x49:
case 0x4A:
case 0x4B:
case 0x4C:
case 0x4D:
case 0x4F:
case 0x50:
case 0x51:
case 0x52:
case 0x53:
case 0x54:
case 0x55:
case 0x57:
case 0x58:
case 0x59:
case 0x5A:
case 0x5B:
case 0x5C:
case 0x5D:
case 0x5F:
case 0x60:
case 0x61:
case 0x62:
case 0x63:
case 0x64:
case 0x65:
case 0x67:
case 0x68:
case 0x69:
case 0x6A:
case 0x6B:
case 0x6C:
case 0x6D:
case 0x6F:
case 0x7F:
case 0x78:
case 0x79:
case 0x7A:
case 0x7B:
case 0x7C:
case 0x7D:
{
var regTarget = Enum.GetName(typeof(RegisterName), (opcode & 0x38) >> 3);
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x07);
return(new Instruction($"LD {regTarget}, {regSource}", count));
}
#endregion
#region LD reg, imm
case 0x06:
case 0x0E:
case 0x16:
case 0x1E:
case 0x26:
case 0x2E:
case 0x3E:
{
var regTarget = Enum.GetName(typeof(RegisterName), (opcode & 0x38) >> 3);
return(new Instruction($"LD {regTarget}, 0x{next():X2}", count));
}
#endregion
#region LD reg, (HL)
case 0x7E:
case 0x46:
case 0x4E:
case 0x56:
case 0x5E:
case 0x66:
case 0x6E:
{
var regTarget = Enum.GetName(typeof(RegisterName), (opcode & 0x38) >> 3);
return(new Instruction($"LD {regTarget}, (HL)", count));
}
#endregion
#region LD (HL), reg
case 0x70:
case 0x71:
case 0x72:
case 0x73:
case 0x74:
case 0x75:
case 0x77:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x07);
return(new Instruction($"LD (HL), {regSource}", count));
}
#endregion
#region LD (HL), imm
case 0x36:
{
return(new Instruction($"LD (HL), 0x{next():X2}", count));
}
#endregion
#region LD A, (BC)
case 0x0A:
{
return(new Instruction("LD A, (BC)", count));
}
#endregion
#region LD A, (DE)
case 0x1A:
{
return(new Instruction("LD A, (DE)", count));
}
#endregion
#region LD A, (C)
case 0xF2:
{
return(new Instruction("LD A, (0xFF00 + C)", count));
}
#endregion
#region LD (C), A
case 0xE2:
{
return(new Instruction("LD (0xFF00 + C), A", count));
}
#endregion
#region LD A, (n)
case 0xF0:
{
return(new Instruction($"LD A, (0xFF{next():X2})", count));
}
#endregion
#region LD (n), A
case 0xE0:
{
return(new Instruction($"LD (0xFF{next():X2}), A", count));
}
#endregion
#region LD A, (nn)
case 0xFA:
{
return(new Instruction($"LD A, (0x{BitUtils.Combine(next(), next()):X4})", count));
}
#endregion
#region LD (nn), A
case 0xEA:
{
return(new Instruction($"LD (0x{BitUtils.Combine(next(), next()):X4}), A", count));
}
#endregion
#region LD A, (HL+)
case 0x2A:
{
return(new Instruction("LD A, (HL+)", count));
}
#endregion
#region LD A, (HL-)
case 0x3A:
{
return(new Instruction("LD A, (HL-)", count));
}
#endregion
#region LD (BC), A
case 0x02:
{
return(new Instruction("LD (BC), A", count));
}
#endregion
#region LD (DE), A
case 0x12:
{
return(new Instruction("LD (DE), A", count));
}
#endregion
#region LD (HL+), A
case 0x22:
{
return(new Instruction("LD (HL+), A", count));
}
#endregion
#region LD (HL-), A
case 0x32:
{
return(new Instruction("LD (HL-), A", count));
}
#endregion
#region LD reg16, imm16
case 0x01:
case 0x11:
case 0x21:
case 0x31:
{
var regTarget = Enum.GetName(typeof(SpecialRegisterName), (opcode & 0x30) >> 4);
return(new Instruction($"LD {regTarget}, 0x{BitUtils.Combine(next(), next()):X4}", count));
}
#endregion
#region LD SP, HL
case 0xF9:
{
return(new Instruction("LD SP, HL", count));
}
#endregion
#region PUSH qq
case 0xF5:
case 0xC5:
case 0xD5:
case 0xE5:
{
var regTarget = Enum.GetName(typeof(SpecialRegisterName), (opcode & 0x30) >> 4);
return(new Instruction($"PUSH {regTarget}", count));
}
#endregion
#region POP qq
case 0xF1:
case 0xC1:
case 0xD1:
case 0xE1:
{
var regTarget = Enum.GetName(typeof(SpecialRegisterName), (opcode & 0x30) >> 4);
return(new Instruction($"POP {regTarget}", count));
}
#endregion
#region LDHL SP, e
case 0xF8:
{
var e = next();
//Instructions.Load(m.Registers.HL, (ushort)(m.Registers.SP.Value + e - 128));
return(new Instruction("LDHL SP, e", count));
}
#endregion
#region LD (nn), SP
case 0x08:
{
return(new Instruction($"LD (0x{BitUtils.Combine(next(), next()):X4}), SP", count));
}
#endregion
#region ADD A, reg
case 0x87:
case 0x80:
case 0x81:
case 0x82:
case 0x83:
case 0x84:
case 0x85:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x7);
return(new Instruction($"ADD A, {regSource}", count));
}
#endregion
#region ADD A, (HL)
case 0x86:
{
return(new Instruction("ADD A, (HL)", count));
}
#endregion
#region ADD A, imm
case 0xC6:
{
return(new Instruction($"ADD A, 0x{next():X2}", count));
}
#endregion
#region ADC A, reg
case 0x8F:
case 0x88:
case 0x89:
case 0x8A:
case 0x8B:
case 0x8C:
case 0x8D:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x7);
return(new Instruction($"ADC A, {regSource}", count));
}
#endregion
#region ADC A, (HL)
case 0x8E:
{
return(new Instruction("ADC A, (HL)", count));
}
#endregion
#region ADC A, imm
case 0xCE:
{
return(new Instruction($"ADC A, 0x{next():X2}", count));
}
#endregion
#region SUB A, reg
case 0x97:
case 0x90:
case 0x91:
case 0x92:
case 0x93:
case 0x94:
case 0x95:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x7);
return(new Instruction($"SUB A, {regSource}", count));
}
#endregion
#region SUB A, (HL)
case 0x96:
{
return(new Instruction("SUB A, (HL)", count));
}
#endregion
#region SUB A, imm
case 0xD6:
{
var immediate = next();
return(new Instruction($"SUB A, 0x{immediate:X2}", count));
}
#endregion
#region SBC A, reg
case 0x9F:
case 0x98:
case 0x99:
case 0x9A:
case 0x9B:
case 0x9C:
case 0x9D:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x7);
return(new Instruction($"SBC A, {regSource}", count));
}
#endregion
#region SBC A, (HL)
case 0x9E:
{
return(new Instruction("SBC A, (HL)", count));
}
#endregion
#region SBC A, imm
case 0xDE:
{
var immediate = next();
return(new Instruction($"SBC A, 0x{immediate:X2}", count));
}
#endregion
#region AND A, reg
case 0xA7:
case 0xA0:
case 0xA1:
case 0xA2:
case 0xA3:
case 0xA4:
case 0xA5:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x7);
return(new Instruction($"AND A, {regSource}", count));
}
#endregion
#region AND A, (HL)
case 0xA6:
{
return(new Instruction("AND A, (HL)", count));
}
#endregion
#region AND A, imm
case 0xE6:
{
var immediate = next();
return(new Instruction($"AND A, 0x{immediate:X2}", count));
}
#endregion
#region OR A, reg
case 0xB7:
case 0xB0:
case 0xB1:
case 0xB2:
case 0xB3:
case 0xB4:
case 0xB5:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x7);
return(new Instruction($"OR A, {regSource}", count));
}
#endregion
#region OR A, (HL)
case 0xB6:
{
return(new Instruction("OR A, (HL)", count));
}
#endregion
#region OR A, imm
case 0xF6:
{
var immediate = next();
return(new Instruction($"OR A, 0x{immediate:X2}", count));
}
#endregion
#region XOR A, reg
case 0xAF:
case 0xA8:
case 0xA9:
case 0xAA:
case 0xAB:
case 0xAC:
case 0xAD:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x7);
return(new Instruction($"XOR A, {regSource}", count));
}
#endregion
#region XOR A, (HL)
case 0xAE:
{
return(new Instruction("XOR A, (HL)", count));
}
#endregion
#region XOR A, imm
case 0xEE:
{
var immediate = next();
return(new Instruction($"XOR A, 0x{immediate:X2}", count));
}
#endregion
#region CP A, reg
case 0xBF:
case 0xB8:
case 0xB9:
case 0xBA:
case 0xBB:
case 0xBC:
case 0xBD:
{
var regSource = Enum.GetName(typeof(RegisterName), opcode & 0x7);
return(new Instruction($"CP A, {regSource}", count));
}
#endregion
#region CP A, (HL)
case 0xBE:
{
return(new Instruction("CP A, (HL)", count));
}
#endregion
#region CP A, imm
case 0xFE:
{
var immediate = next();
return(new Instruction($"CP A, 0x{immediate:X2}", count));
}
#endregion
#region INC reg
case 0x3C:
case 0x04:
case 0x0C:
case 0x14:
case 0x1C:
case 0x24:
case 0x2C:
{
var regSource = Enum.GetName(typeof(RegisterName), (opcode & 0x38) >> 3);
return(new Instruction($"INC {regSource}", count));
}
#endregion
#region INC (HL)
case 0x34:
{
return(new Instruction("INC (HL)", count));
}
#endregion
#region DEC reg
case 0x3D:
case 0x05:
case 0x0D:
case 0x15:
case 0x1D:
case 0x25:
case 0x2D:
{
var regSource = Enum.GetName(typeof(RegisterName), (opcode & 0x38) >> 3);
return(new Instruction($"DEC {regSource}", count));
}
#endregion
#region DEC (HL)
case 0x35:
{
return(new Instruction("DEC (HL)", count));
}
#endregion
#region ADD HL, reg16
case 0x09:
case 0x19:
case 0x29:
case 0x39:
{
var regSource = Enum.GetName(typeof(PairedRegisterName), (opcode & 0x30) >> 4);
return(new Instruction($"ADD HL, {regSource}", count));
}
#endregion
// TODO
#region ADD SP, e
case 0xE8:
{
// ...
var e = next();
return(new Instruction("ADD SP, e", count));
}
#endregion
#region INC reg16
case 0x03:
case 0x13:
case 0x23:
case 0x33:
{
var regSource = Enum.GetName(typeof(PairedRegisterName), (opcode & 0x30) >> 4);
return(new Instruction($"INC {regSource}", count));
}
#endregion
#region DEC reg16
case 0x0B:
case 0x1B:
case 0x2B:
case 0x3B:
{
var regSource = Enum.GetName(typeof(PairedRegisterName), (opcode & 0x30) >> 4);
return(new Instruction($"DEC {regSource}", count));
}
#endregion
#region RLCA
case 0x07:
{
return(new Instruction("RLCA", count));
}
#endregion
#region RLA
case 0x17:
{
return(new Instruction("RLA", count));
}
#endregion
#region RRCA
case 0x0F:
{
return(new Instruction("RRCA", count));
}
#endregion
#region RRA
case 0x1F:
{
return(new Instruction("RRA", count));
}
#endregion
case 0xCB:
{
return(DisassembleCBInstruction(lookahead));
}
#region JP imm16
case 0xC3:
{
var immediate = BitUtils.Combine(next(), next());
return(new Instruction($"JP 0x{immediate:X4}", count));
}
#endregion
#region JP cc, imm16
case 0xC2:
case 0xCA:
case 0xD2:
case 0xDA:
{
var immediate = BitUtils.Combine(next(), next());
var condition = Enum.GetName(typeof(JumpCondition), (opcode & 0x18) >> 3);
return(new Instruction($"JP {condition}, {immediate}", count));
}
#endregion
// TODO: what is e-2??
#region JR e
case 0x18:
{
var e = (sbyte)next();
return(new Instruction($"JR {e}", count));
}
#endregion
// TODO: e
#region JR cc, e
case 0x20:
case 0x28:
case 0x30:
case 0x38:
{
var condition = Enum.GetName(typeof(JumpCondition), (opcode & 0x18) >> 3);
var offset = (sbyte)next();
return(new Instruction($"JR {condition}, {offset}", count));
}
#endregion
#region JP (HL)
case 0xE9:
{
return(new Instruction("JP (HL)", count));
}
#endregion
#region CALL imm16
case 0xCD:
{
var immediate = BitUtils.Combine(next(), next());
return(new Instruction($"CALL 0x{immediate:X4}", count));
}
#endregion
#region CALL cc, imm16
case 0xC4:
case 0xCC:
case 0xD4:
case 0xDC:
{
var immediate = BitUtils.Combine(next(), next());
var condition = Enum.GetName(typeof(JumpCondition), (opcode & 0x18) >> 3);
return(new Instruction($"CALL {condition}, {immediate}", count));
}
#endregion
#region RET
case 0xC9:
{
return(new Instruction("RET", count));
}
#endregion
#region RETI
case 0xD9:
{
return(new Instruction("RETI", count));
}
#endregion
#region RET cc
case 0xC0:
case 0xC8:
case 0xD0:
case 0xD8:
{
var condition = Enum.GetName(typeof(JumpCondition), (opcode & 0x18) >> 3);
return(new Instruction($"RET {condition}", count));
}
#endregion
#region RST t
case 0xC7:
case 0xCF:
case 0xD7:
case 0xDF:
case 0xE7:
case 0xEF:
case 0xF7:
case 0xFF:
{
var resetAddr = (byte)(((opcode & 0b0011_1000) >> 3) * 0x08);
return(new Instruction($"RST 0x{resetAddr:X2}", count));
}
#endregion
#region DAA
case 0x27:
{
return(new Instruction("DAA", count));
}
#endregion
#region CPL
case 0x2F:
{
return(new Instruction("CPL", count));
}
#endregion
#region CCF
case 0x3F:
{
return(new Instruction("CCF", count));
}
#endregion
#region SCF
case 0x37:
{
return(new Instruction("SCF", count));
}
#endregion
#region DI
case 0xF3:
{
return(new Instruction("DI", count));
}
#endregion
#region EI
case 0xFB:
{
return(new Instruction("EI", count));
}
#endregion
#region HALT
case 0x76:
{
return(new Instruction("HALT", count));
}
#endregion
#region STOP
case 0x10:
{
return(new Instruction("STOP", count));
}
#endregion
default:
return(new Instruction("???", 1));
//throw new InvalidOperationException("Invalid opcode.");
}
}
