private static Dictionary<int, Opcode> Assemble(List<Line> source)
{
Dictionary<int, Opcode> binary = new Dictionary<int, Opcode>();
Opcode op = null;
RomItem[] ria = null;
int address = 0;
// 1st pass [Parse each command]
foreach (Line line in source)
{
op = AssembleLine(line);
if (op != null)
{
// regular instruction
if (!op.Pseudo)
{
ria = new RomItem[1];
ria[0] = new RomItem(address, op);
IncreaseAddress(ref address);
}
else // Handle Assembler pseudo instructions
{
ria = HandlePseudoInstruction(ref address, op);
}
// 2nd pass [Resolve each Pseudo command]
foreach (RomItem ri in ria)
{
line.AddRomItem(ri);
try
{
binary.Add(ri.Address, ri.Opcode);
}
catch
{
line.SetError("Address is overlapping with other code");
}
}
}
}
// 3rd pass [Resolve labels]
ResolveLabels(binary);
return binary;
}
public void AddRomItem(RomItem ri)
{
ArrayList arl = new ArrayList(Opcodes);
arl.Add(ri);
Opcodes = (RomItem[])arl.ToArray(typeof(RomItem));
}
private static RomItem[] HandlePseudoInstruction(ref int address, Opcode op)
{
ArrayList arl = new ArrayList();
RomItem ri;
if (op.Command == Command.org) // ORiGin
{
address = op.Imm16;
if (!String.IsNullOrEmpty(op.Label))
op.SourceLine.SetError("ORG command is not allowed to have a label");
}
else if (op.Command == Command.li) // Load Immediate
{
ri = new RomItem(address, OpcodeDictionary.Get("movl"));
ri.Opcode.Register1 = op.Register1;
if (op.Type == OpcodeType.TwoArg_RegImm16label)
{
ri.Opcode.Imm16label = op.Imm16label;
ri.Opcode.Type = OpcodeType.TwoArg_RegImm16label_l;
}
else
{
ri.Opcode.Imm8 = op.Imm16 & 0xFF;
ri.Opcode.Type = OpcodeType.TwoArg_RegImm8;
}
ri.Opcode.Label = op.Label;
ri.Opcode.SetSourceLine(op.SourceLine);
arl.Add(ri);
IncreaseAddress(ref address);
ri = new RomItem(address, OpcodeDictionary.Get("movh"));
ri.Opcode.Register1 = op.Register1;
if (op.Type == OpcodeType.TwoArg_RegImm16label)
{
ri.Opcode.Imm16label = op.Imm16label;
ri.Opcode.Type = OpcodeType.TwoArg_RegImm16label_h;
}
else
{
ri.Opcode.Imm8 = op.Imm16 >> 8;
ri.Opcode.Type = OpcodeType.TwoArg_RegImm8;
}
ri.Opcode.SetSourceLine(op.SourceLine);
arl.Add(ri);
IncreaseAddress(ref address);
}
else if (op.Command == Command.jrl) // JumpRegisterLabel
{
ri = new RomItem(address, OpcodeDictionary.Get("movl"));
ri.Opcode.Register1 = op.Register1;
//ri.Opcode.Imm8 = op.Imm16 & 0xFF;
ri.Opcode.Imm16label = op.Imm16label;
ri.Opcode.Type = OpcodeType.TwoArg_RegImm16label_l;
ri.Opcode.Label = op.Label;
ri.Opcode.SetSourceLine(op.SourceLine);
arl.Add(ri);
IncreaseAddress(ref address);
ri = new RomItem(address, OpcodeDictionary.Get("movh"));
ri.Opcode.Register1 = op.Register1;
//ri.Opcode.Imm8 = op.Imm16 >> 8;
ri.Opcode.Imm16label = op.Imm16label;
ri.Opcode.Type = OpcodeType.TwoArg_RegImm16label_h;
ri.Opcode.SetSourceLine(op.SourceLine);
arl.Add(ri);
IncreaseAddress(ref address);
ri = new RomItem(address, OpcodeDictionary.Get("jr"));
ri.Opcode.Register1 = op.Register1;
ri.Opcode.Type = OpcodeType.OneArg_Reg;
ri.Opcode.SetSourceLine(op.SourceLine);
arl.Add(ri);
IncreaseAddress(ref address);
}
else if (op.Command == Command.dw) // DataWord
{
ri = new RomItem(address, OpcodeDictionary.Get("dw"));
ri.Opcode.Data16 = op.Data16;
ri.Opcode.Type = OpcodeType.OneArg_Data16;
ri.Opcode.Label = op.Label;
ri.Opcode.SetSourceLine(op.SourceLine);
arl.Add(ri);
IncreaseAddress(ref address);
}
return (RomItem[])arl.ToArray(typeof(RomItem));
}
