public static void RequireOpcodeFlag(OpcodeFlag flag, OpcodeFlag[] acceptable)
{
for (int i = 0; i < acceptable.Length; i++)
if (flag.HasFlag(acceptable[i]))
return;
throw new Exception($"Opcode flag of '{flag}' is unsupported for this opcode");
}
private List <ushort> AssembleJSR(List <string> param, OpcodeFlag opcodeFlag, ParserState state)
{
if (opcodeFlag.HasFlag(OpcodeFlag.FarJump))
{
Guard.RequireParamCountMinMax(param, 1, 2); // allow two params for immediate far jump.
return(state.Parser.AssembleJMI(0x01B9, param[0], param.Count == 2 ? param[1] : null, state));
}
Guard.RequireParamCountExact(param, 1);
return(state.Parser.AssembleJMI(0x00B9, param[0], null, state));
}
private List <ushort> AssembleJMP(List <string> param, OpcodeFlag opcodeFlag, ParserState state)
{
Guard.RequireOpcodeFlag(opcodeFlag, new[] { OpcodeFlag.BitWidth16 });
if (opcodeFlag.HasFlag(OpcodeFlag.FarJump))
{
Guard.RequireParamCountMinMax(param, 1, 2);
return(state.Parser.AssembleJMI(0x01B8, param[0], param.Count == 2 ? param[1] : null, state));
}
Guard.RequireParamCountExact(param, 1);
return(state.Parser.AssembleJMI(0x00B8, param[0], null, state));
}
public static void RequireOpcodeFlag(OpcodeFlag flag, OpcodeFlag[] acceptable)
{
for (int i = 0; i < acceptable.Length; i++)
{
if (flag.HasFlag(acceptable[i]))
{
return;
}
}
throw new Exception($"Opcode flag of '{flag}' is unsupported for this opcode");
}
private List <ushort> AssembleRTS(List <string> param, OpcodeFlag opcodeFlag, ParserState state)
{
if (opcodeFlag.HasFlag(OpcodeFlag.FarJump))
{
return(new List <ushort> {
0x01B4
}); // RTS.F
}
return(new List <ushort> {
0x00B4
}); // RTS
}
private List<ushort> AssembleRTS(List<string> param, OpcodeFlag opcodeFlag, ParserState state)
{
if (opcodeFlag.HasFlag(OpcodeFlag.FarJump))
{
return new List<ushort> { 0x01B4 }; // RTS.F
}
return new List<ushort> { 0x00B4 }; // RTS
}
private List<ushort> AssembleJSR(List<string> param, OpcodeFlag opcodeFlag, ParserState state)
{
if (opcodeFlag.HasFlag(OpcodeFlag.FarJump))
{
Guard.RequireParamCountMinMax(param, 1, 2); // allow two params for immediate far jump.
return state.Parser.AssembleJMI(0x01B9, param[0], param.Count == 2 ? param[1] : null, state);
}
Guard.RequireParamCountExact(param, 1);
return state.Parser.AssembleJMI(0x00B9, param[0], null, state);
}
private List<ushort> AssembleJMP(List<string> param, OpcodeFlag opcodeFlag, ParserState state)
{
Guard.RequireOpcodeFlag(opcodeFlag, new[] { OpcodeFlag.BitWidth16 });
if (opcodeFlag.HasFlag(OpcodeFlag.FarJump))
{
Guard.RequireParamCountMinMax(param, 1, 2);
return state.Parser.AssembleJMI(0x01B8, param[0], param.Count == 2 ? param[1] : null, state);
}
Guard.RequireParamCountExact(param, 1);
return state.Parser.AssembleJMI(0x00B8, param[0], null, state);
}
private List<ushort> AssembleALU(ushort opcode, string param1, string param2, OpcodeFlag opcodeFlag, ParserState state)
{
Param p1 = ParseParam(param1);
Param p2 = ParseParam(param2);
if (p1.AddressingMode != AddressingMode.Register)
{
throw new Exception("ALU instruction first operand must be a general purpose register");
}
ushort addressingmode = 0x0000;
switch (p2.AddressingMode)
{
case AddressingMode.None:
return null;
case AddressingMode.Immediate:
// .000 000e Immediate LOD R0, $1234 +1m
// special case: alu.8 immediate with value greater than $FF should raise a warning...
if (opcodeFlag == OpcodeFlag.BitWidth8 && p2.ImmediateWordShort >= 256)
{
throw new Exception("8-bit load operation with an immediate value of greater than 8 bits");
}
addressingmode = 0x0000;
if (p2.UsesExtraDataSegment)
throw new Exception("Immediate addressing mode cannot use extra data segment");
break;
case AddressingMode.Absolute:
// s000 001e Absolute LOD R0, [$1234] +2m
addressingmode = 0x0200;
if (p2.UsesExtraDataSegment)
addressingmode |= 0x8000;
break;
case AddressingMode.ControlRegister:
// .000 1ppp Control register LOD R0, PS
// can't use eightbit mode with proc regs...
if (opcodeFlag.HasFlag(OpcodeFlag.BitWidth8))
throw new Exception("ALU instructions with status register operands do not support 8-bit mode");
if (p2.UsesExtraDataSegment)
throw new Exception("Control register addressing mode cannot use extra data segment");
addressingmode = (ushort)(0x0800 | ((p2.RegisterIndex & 0x0007) << 8));
p2.RegisterIndex = 0; // must wipe out control register index, as it is used later in this subroutine.
break;
case AddressingMode.Register:
// .001 rrre Register LOD R0, r1
addressingmode = 0x1000;
if (p2.UsesExtraDataSegment)
throw new Exception("Register addressing mode cannot use extra data segment");
break;
case AddressingMode.Indirect:
// s010 rrre Indirect LOD R0, [r1] +1m
addressingmode = 0x2000;
if (p2.UsesExtraDataSegment)
addressingmode |= 0x8000;
break;
case AddressingMode.IndirectOffset:
// s011 rrre Indirect Offset LOD R0, [r1,$1234] +2m
addressingmode = 0x3000;
if (p2.UsesExtraDataSegment)
addressingmode |= 0x8000;
break;
case AddressingMode.IndirectIndexed:
// s1ii rrre Indirect Indexed LOD R0, [r1,i2] +1m
int index_register = (p2.RegisterIndex & 0x0300) << 4;
addressingmode = (ushort)(0x4000 | index_register);
if (p2.UsesExtraDataSegment)
addressingmode |= 0x8000;
break;
default:
throw new Exception("Unknown addressing mode");
}
ushort bitwidth = 0x0000;
if (opcodeFlag == OpcodeFlag.BitWidth8)
bitwidth = 0x0100;
// FEDC BA98 7654 3210
// AAAA rrrE OOOO ORRR
m_Code.Clear();
m_Code.Add((ushort)(opcode | addressingmode | bitwidth | (p1.RegisterIndex & 0x0007) | ((p2.RegisterIndex & 0x0007) << 9)));
if (p2.HasLabel)
{
state.Labels.Add((ushort)(state.Code.Count + m_Code.Count * c_InstructionSize), p2.Label);
m_Code.Add(0xDEAD);
}
else if (p2.HasImmediateWord)
{
m_Code.Add(p2.ImmediateWordShort);
}
return m_Code;
}
private List <ushort> AssembleALU(ushort opcode, string param1, string param2, OpcodeFlag opcodeFlag, ParserState state)
{
Param p1 = ParseParam(param1);
Param p2 = ParseParam(param2);
if (p1.AddressingMode != AddressingMode.Register)
{
throw new Exception("ALU instruction first operand must be a general purpose register");
}
ushort addressingmode = 0x0000;
switch (p2.AddressingMode)
{
case AddressingMode.None:
return(null);
case AddressingMode.Immediate:
// .000 000e Immediate LOD R0, $1234 +1m
// special case: alu.8 immediate with value greater than $FF should raise a warning...
if (opcodeFlag == OpcodeFlag.BitWidth8 && p2.ImmediateWordShort >= 256)
{
throw new Exception("8-bit load operation with an immediate value of greater than 8 bits");
}
addressingmode = 0x0000;
if (p2.UsesExtraDataSegment)
{
throw new Exception("Immediate addressing mode cannot use extra data segment");
}
break;
case AddressingMode.Absolute:
// s000 001e Absolute LOD R0, [$1234] +2m
addressingmode = 0x0200;
if (p2.UsesExtraDataSegment)
{
addressingmode |= 0x8000;
}
break;
case AddressingMode.ControlRegister:
// .000 1ppp Control register LOD R0, PS
// can't use eightbit mode with proc regs...
if (opcodeFlag.HasFlag(OpcodeFlag.BitWidth8))
{
throw new Exception("ALU instructions with status register operands do not support 8-bit mode");
}
if (p2.UsesExtraDataSegment)
{
throw new Exception("Control register addressing mode cannot use extra data segment");
}
addressingmode = (ushort)(0x0800 | ((p2.RegisterIndex & 0x0007) << 8));
p2.RegisterIndex = 0; // must wipe out control register index, as it is used later in this subroutine.
break;
case AddressingMode.Register:
// .001 rrre Register LOD R0, r1
addressingmode = 0x1000;
if (p2.UsesExtraDataSegment)
{
throw new Exception("Register addressing mode cannot use extra data segment");
}
break;
case AddressingMode.Indirect:
// s010 rrre Indirect LOD R0, [r1] +1m
addressingmode = 0x2000;
if (p2.UsesExtraDataSegment)
{
addressingmode |= 0x8000;
}
break;
case AddressingMode.IndirectOffset:
// s011 rrre Indirect Offset LOD R0, [r1,$1234] +2m
addressingmode = 0x3000;
if (p2.UsesExtraDataSegment)
{
addressingmode |= 0x8000;
}
break;
case AddressingMode.IndirectIndexed:
// s1ii rrre Indirect Indexed LOD R0, [r1,i2] +1m
int index_register = (p2.RegisterIndex & 0x0300) << 4;
addressingmode = (ushort)(0x4000 | index_register);
if (p2.UsesExtraDataSegment)
{
addressingmode |= 0x8000;
}
break;
default:
throw new Exception("Unknown addressing mode");
}
ushort bitwidth = 0x0000;
if (opcodeFlag == OpcodeFlag.BitWidth8)
{
bitwidth = 0x0100;
}
// FEDC BA98 7654 3210
// AAAA rrrE OOOO ORRR
m_Code.Clear();
m_Code.Add((ushort)(opcode | addressingmode | bitwidth | (p1.RegisterIndex & 0x0007) | ((p2.RegisterIndex & 0x0007) << 9)));
if (p2.HasLabel)
{
state.Labels.Add((ushort)(state.Code.Count + m_Code.Count * c_InstructionSize), p2.Label);
m_Code.Add(0xDEAD);
}
else if (p2.HasImmediateWord)
{
m_Code.Add(p2.ImmediateWordShort);
}
return(m_Code);
}
