public OpcodeTableEntry(Action f, string d, ArgType[] a, OpcodeTable nt = null)
{
func = f;
dasm = d;
args = a;
nextTable = nt;
}
protected void DoExecute()
{
byte opCode;
int offset = 0;
OpcodeTableEntry operation;
OpcodeTable current = opcodeTable;
ushort start = pc;
while (true)
{
if (execIntVector)
{
opCode = intVector;
tStates += 6;
}
else
{
opCode = Read8((ushort)(pc + offset));
pc++;
tStates++;
}
IncR();
operation = current.entries[opCode];
if (operation == null)
{
throw new NullReferenceException(
string.Format("Operation is not implemented at 0x{0:X4}",
start));
}
if (operation.func != null)
{
pc = (ushort)(pc - offset);
operation.func();
pc = (ushort)(pc + offset);
break;
}
if (operation.nextTable != null)
{
current = operation.nextTable;
offset = current.opcodeOffset;
if (offset > 0)
{
DecR();
}
}
else
{
break;
}
}
}
virtual protected void CreateTables()
{
// Creating tables
opcodeTable = new OpcodeTable();
opcodeTableCB = new OpcodeTable();
opcodeTableDD = new OpcodeTable();
opcodeTableED = new OpcodeTable();
opcodeTableFD = new OpcodeTable();
opcodeTableDDCB = new OpcodeTable(1);
opcodeTableFDCB = new OpcodeTable(1);
// Linking tables
opcodeTable.entries[0xCB] = new OpcodeTableEntry(null, "", null, opcodeTableCB);
opcodeTable.entries[0xDD] = new OpcodeTableEntry(null, "", null, opcodeTableDD);
opcodeTable.entries[0xED] = new OpcodeTableEntry(null, "", null, opcodeTableED);
opcodeTable.entries[0xFD] = new OpcodeTableEntry(null, "", null, opcodeTableFD);
opcodeTableDD.entries[0xCB] = new OpcodeTableEntry(null, "", null, opcodeTableDDCB);
opcodeTableFD.entries[0xCB] = new OpcodeTableEntry(null, "", null, opcodeTableFDCB);
opcodeTableDD.entries[0xDD] = new OpcodeTableEntry(null, "", null, opcodeTableDD);
opcodeTableFD.entries[0xDD] = new OpcodeTableEntry(null, "", null, opcodeTableDD);
opcodeTableDD.entries[0xFD] = new OpcodeTableEntry(null, "", null, opcodeTableFD);
opcodeTableFD.entries[0xFD] = new OpcodeTableEntry(null, "", null, opcodeTableFD);
}
// Disassemble(ushort addr) disassembles a single CPU operation
// based at addr and puts it into result variable. Returns the addr
// of the next instruction
//
public ushort Disassemble(ushort addr, out string result)
{
ushort start = addr;
byte opCode;
int offset = 0;
OpcodeTableEntry operation;
OpcodeTable current = opcodeTable;
while (true)
{
opCode = memory.Read8((ushort)(addr + offset));
addr++;
operation = current.entries[opCode];
if (operation == null)
{
result = string.Format("Error disassembling at 0x{0:X4}", start);
return(addr);
}
if (operation.func != null)
{
addr = (ushort)(addr - offset);
object[] args = new object[operation.args.Length];
for (int j = 0; j < operation.args.Length; j++)
{
var argType = operation.args[j];
switch (argType)
{
case ArgType.Byte:
byte value = Read8(addr++);
if (dasmMode == DisassembleMode.Dec)
{
args[j] = value;
}
else
{
args[j] = string.Format("${0:X2}", value);
}
break;
case ArgType.Word:
ushort value16 = Read16(addr);
addr += 2;
if (dasmMode == DisassembleMode.Dec)
{
args[j] = value16;
}
else
{
args[j] = string.Format("${0:X4}", value16);
}
break;
case ArgType.Offset:
var idxOffset = (SByte)Read8(addr++);
string offFormat;
if (idxOffset >= 0)
{
offFormat = "+{0}";
}
else
{
offFormat = "{0}";
}
args[j] = string.Format(offFormat, idxOffset);
break;
}
}
addr = (ushort)(addr + offset);
result = string.Format(operation.dasm, args);
return(addr);
}
if (operation.nextTable != null)
{
current = operation.nextTable;
offset = current.opcodeOffset;
}
else
{
break;
}
}
result = "Disassembler logic error";
return(addr);
}