private DisassemblyItem DecodeInstruction(ushort address, OperationMapBase opInfo)
{
// --- By default, unknown codes are NOP operations
var disassemblyItem = new DisassemblyItem(address)
{
OpCodes = _currentOpCodes.ToString(),
Instruction = "nop",
LastAddress = (ushort)(_offset - 1)
};
if (opInfo == null)
{
return(disassemblyItem);
}
// --- We have a real operation, it's time to decode it
var pragmaCount = 0;
disassemblyItem.Instruction = opInfo.InstructionPattern;
do
{
var pragmaIndex = disassemblyItem.Instruction.IndexOf("^", StringComparison.Ordinal);
if (pragmaIndex < 0)
{
break;
}
pragmaCount++;
ProcessPragma(disassemblyItem, pragmaIndex);
} while (pragmaCount < 4);
// --- We've fully processed the instruction
disassemblyItem.OpCodes = _currentOpCodes.ToString();
disassemblyItem.LastAddress = (ushort)(_offset - 1);
return(disassemblyItem);
}
/// <summary>
/// Generates byte array output for the specified section
/// </summary>
/// <param name="section">Section information</param>
private void GenerateByteArray(MemorySection section)
{
var length = section.EndAddress - section.StartAddress + 1;
for (var i = 0; i < length; i += 8)
{
var sb = new StringBuilder(200);
sb.Append(".defb ");
for (var j = 0; j < 8; j++)
{
if (i + j >= length)
{
break;
}
if (j > 0)
{
sb.Append(", ");
}
sb.AppendFormat("#{0:X2}", MemoryContents[section.StartAddress + i + j]);
}
var item = new DisassemblyItem((ushort)(section.StartAddress + i))
{
Instruction = sb.ToString()
};
_output.AddItem(item);
}
}
/// <summary>
/// Checks if the disassembler should enter into Spectrum-specific mode after
/// the specified disassembly item.
/// </summary>
/// <param name="item">Item used to check the Spectrum-specific mode</param>
/// <returns>
/// True, to move to the Spectrum-specific mode; otherwise, false
/// </returns>
private bool ShouldEnterSpectrumSpecificMode(DisassemblyItem item)
{
// --- Check for Spectrum 48K RST #08
if ((DisassemblyFlags & SpectrumSpecificDisassemblyFlags.Spectrum48Rst08) != 0 &&
item?.OpCodes.Trim() == "CF")
{
_spectMode = SpectrumSpecificMode.Spectrum48Rst08;
item.HardComment = "(Report error)";
return(true);
}
// --- Check for Spectrum 48K RST #28
if ((DisassemblyFlags & SpectrumSpecificDisassemblyFlags.Spectrum48Rst28) != 0 &&
(item?.OpCodes.Trim() == "EF" || // --- RST #28
item?.OpCodes.Trim() == "CD 5E 33" || // --- CALL 335E
item?.OpCodes.Trim() == "CD 62 33")) // --- CALL 3362
{
_spectMode = SpectrumSpecificMode.Spectrum48Rst28;
_seriesCount = 0;
item.HardComment = "(Invoke Calculator)";
return(true);
}
return(false);
}
/// <summary>
/// Generates word array output for the specified section
/// </summary>
/// <param name="section">Section information</param>
private void GenerateWordArray(MemorySection section)
{
var length = section.EndAddress - section.StartAddress + 1;
for (var i = 0; i < length; i += 8)
{
if (i + 1 >= length) break;
var sb = new StringBuilder(200);
sb.Append(".defw ");
for (var j = 0; j < 8; j += 2)
{
if (i + j + 1 >= length) break;
if (j > 0)
{
sb.Append(", ");
}
var value = (ushort)(MemoryContents[section.StartAddress + i + j * 2] +
(MemoryContents[section.StartAddress + i + j * 2 + 1] << 8));
sb.AppendFormat("#{0:X4}", value);
}
var item = new DisassemblyItem((ushort)(section.StartAddress + i))
{
Instruction = sb.ToString()
};
_output.AddItem(item);
}
if (length % 2 == 1)
{
GenerateByteArray(new MemorySection(section.EndAddress, section.EndAddress));
}
}
/// <summary>
/// Generates skip output for the specified section
/// </summary>
/// <param name="section">Section information</param>
private void GenerateSkipOutput(MemorySection section)
{
var item = new DisassemblyItem(section.StartAddress)
{
Instruction = $".skip {section.EndAddress - section.StartAddress + 1:X4}H"
};
_output.AddItem(item);
}
/// <summary>
/// Generates byte array output for the specified section
/// </summary>
/// <param name="section">Section information</param>
/// <param name="rowBytes">Number of bytes to add to a .DEFG row</param>
private void GenerateDefgArray(MemorySection section, int rowBytes)
{
var length = section.EndAddress - section.StartAddress + 1;
var sb = new StringBuilder(200);
var opCodes = new StringBuilder();
var byteInRow = 0;
var startAddr = section.StartAddress;
for (var i = 0; i < length; i++)
{
if (byteInRow == 0)
{
sb.Append(".defg");
}
var content = MemoryContents[section.StartAddress + i];
opCodes.Append($"{content:X2} ");
sb.Append(" ");
for (var j = 0; j < 8; j++)
{
sb.Append((content & 0x80) == 0 ? "." : "X");
content <<= 1;
}
byteInRow++;
if (byteInRow >= rowBytes)
{
byteInRow = 0;
var item = new DisassemblyItem(startAddr)
{
Instruction = sb.ToString(),
OpCodes = opCodes.ToString()
};
_output.AddItem(item);
startAddr = (ushort)(section.StartAddress + i + 1);
sb.Clear();
opCodes.Clear();
}
}
if (byteInRow == 0)
{
return;
}
var lastItem = new DisassemblyItem(startAddr)
{
Instruction = sb.ToString(),
OpCodes = opCodes.ToString()
};
_output.AddItem(lastItem);
}
/// <summary>
/// Checks if the disassembler should enter into Spectrum-specific mode after
/// the specified disassembly item.
/// </summary>
/// <param name="item">Item used to check the Spectrum-specific mode</param>
/// <returns>
/// True, to move to the Spectrum-specific mode; otherwise, false
/// </returns>
private bool ShouldEnterSpectrumSpecificMode(DisassemblyItem item)
{
// --- Check if we find flags for the bank of the disassembly item
var bank = item.Address >> 14;
if (!DisassemblyFlags.TryGetValue(bank, out var flags) ||
flags == SpectrumSpecificDisassemblyFlags.None)
{
return(false);
}
// --- Check for Spectrum 48K RST #08
if ((flags & SpectrumSpecificDisassemblyFlags.Spectrum48Rst08) != 0 &&
item.OpCodes.Trim() == "CF")
{
_spectMode = SpectrumSpecificMode.Spectrum48Rst08;
item.HardComment = "(Report error)";
return(true);
}
// --- Check for Spectrum 48K RST #28
if ((flags & SpectrumSpecificDisassemblyFlags.Spectrum48Rst28) != 0 &&
(item.OpCodes.Trim() == "EF" || // --- RST #28
item.OpCodes.Trim() == "CD 5E 33" || // --- CALL 335E
item.OpCodes.Trim() == "CD 62 33")) // --- CALL 3362
{
_spectMode = SpectrumSpecificMode.Spectrum48Rst28;
_seriesCount = 0;
item.HardComment = "(Invoke Calculator)";
return(true);
}
// --- Check for Spectrum 128K RST #28
if ((flags & SpectrumSpecificDisassemblyFlags.Spectrum128Rst28) != 0 &&
item.OpCodes.Trim() == "EF")
{
_spectMode = SpectrumSpecificMode.Spectrum128Rst8;
item.HardComment = "(Call Spectrum 48 ROM)";
return(true);
}
return(false);
}
/// <summary>
/// Disassembles the subsequent operation as Spectrum-specific
/// </summary>
/// <param name="carryOn">
/// True, if the disassembler still remains in Spectrum-specific mode;
/// otherwise, false
/// </param>
/// <returns>Disassembled operation</returns>
private DisassemblyItem DisassembleSpectrumSpecificOperation(out bool carryOn)
{
if (_spectMode == SpectrumSpecificMode.None)
{
carryOn = false;
return(null);
}
DisassemblyItem item = null;
carryOn = false;
// --- Handle Spectrum 48 Rst08
if (_spectMode == SpectrumSpecificMode.Spectrum48Rst08)
{
// --- The next byte is the operation code
var address = (ushort)_offset;
var errorCode = Fetch();
_spectMode = SpectrumSpecificMode.None;
item = new DisassemblyItem(address)
{
OpCodes = $"{errorCode:X2}",
Instruction = $".defb #{errorCode:X2}",
HardComment = $"(error code: #{errorCode:X2})",
LastAddress = (ushort)(_offset - 1)
};
}
// --- Handle Spectrum 48 Rst08
if (_spectMode == SpectrumSpecificMode.Spectrum48Rst28)
{
var address = (ushort)_offset;
var calcCode = Fetch();
item = DisassembleCalculatorEntry(address, calcCode, out carryOn);
}
if (!carryOn)
{
_spectMode = SpectrumSpecificMode.None;
}
return(item);
}
/// <summary>
/// Adds a new item to the output
/// </summary>
/// <param name="item">Disassembly item to add</param>
public void AddItem(DisassemblyItem item)
{
_outputItems.Add(item);
_outputByAddress.Add(item.Address, item);
}
private void ProcessPragma(DisassemblyItem disassemblyItem, int pragmaIndex)
{
var instruction = disassemblyItem.Instruction;
if (pragmaIndex >= instruction.Length)
{
return;
}
var pragma = instruction[pragmaIndex + 1];
var replacement = "";
var symbolPresent = false;
var symbolValue = (ushort)0x000;
switch (pragma)
{
case '8':
// --- #8: 8-bit value defined on bit 3, 4 and 5 ($00, $10, ..., $38)
var val = (byte)(_opCode & 0x38);
replacement = ByteToString(val);
break;
case 'b':
// --- #b: bit index defined on bit 3, 4 and 5 in bit operations
var bit = (byte)((_opCode & 0x38) >> 3);
replacement = bit.ToString();
break;
case 'r':
// --- #r: relative label (8 bit offset)
var distance = Fetch();
var labelAddr = (ushort)(_opOffset + 2 + (sbyte)distance);
_output.CreateLabel(labelAddr, (ushort)_opOffset);
replacement = GetLabelName(labelAddr);
symbolPresent = true;
disassemblyItem.HasLabelSymbol = true;
symbolValue = labelAddr;
break;
case 'L':
// --- #L: absolute label (16 bit address)
var target = FetchWord();
disassemblyItem.TargetAddress = target;
_output.CreateLabel(target, (ushort)_opOffset);
replacement = GetLabelName(target);
symbolPresent = true;
disassemblyItem.HasLabelSymbol = true;
symbolValue = target;
break;
case 'q':
// --- #q: 8-bit registers named on bit 3, 4 and 5 (B, C, ..., (HL), A)
var regqIndex = (_opCode & 0x38) >> 3;
replacement = s_Q8Regs[regqIndex];
break;
case 's':
// --- #q: 8-bit registers named on bit 0, 1 and 2 (B, C, ..., (HL), A)
var regsIndex = _opCode & 0x07;
replacement = s_Q8Regs[regsIndex];
break;
case 'Q':
// --- #Q: 16-bit register pair named on bit 4 and 5 (BC, DE, HL, SP)
var regQIndex = (_opCode & 0x30) >> 4;
replacement = s_Q16Regs[regQIndex];
break;
case 'R':
// --- #Q: 16-bit register pair named on bit 4 and 5 (BC, DE, HL, AF)
var regRIndex = (_opCode & 0x30) >> 4;
replacement = s_R16Regs[regRIndex];
break;
case 'B':
// --- #B: 8-bit value from the code
var value = Fetch();
replacement = ByteToString(value);
symbolPresent = true;
symbolValue = value;
break;
case 'W':
// --- #W: 16-bit word from the code
var word = FetchWord();
replacement = WordToString(word);
symbolPresent = true;
symbolValue = word;
break;
case 'X':
// --- #X: Index register (IX or IY) according to current index mode
replacement = _indexMode == 1 ? "ix": "iy";
break;
case 'l':
// --- #l: Lowest 8 bit index register (XL or YL) according to current index mode
replacement = _indexMode == 1 ? "xl" : "yl";
break;
case 'h':
// --- #h: Highest 8 bit index register (XH or YH) according to current index mode
replacement = _indexMode == 1 ? "xh" : "yh";
break;
case 'D':
// --- #D: Index operation displacement
if (_displacement.HasValue)
{
replacement = (sbyte)_displacement < 0
? $"-{ByteToString((byte) (0x100 - _displacement.Value))}"
: $"+{ByteToString(_displacement.Value)}";
}
break;
}
if (symbolPresent && !string.IsNullOrEmpty(replacement))
{
disassemblyItem.TokenPosition = pragmaIndex;
disassemblyItem.TokenLength = replacement.Length;
disassemblyItem.HasSymbol = true;
disassemblyItem.SymbolValue = symbolValue;
}
disassemblyItem.Instruction = instruction.Substring(0, pragmaIndex)
+ (replacement ?? "")
+ instruction.Substring(pragmaIndex + 2);
}
/// <summary>
/// Disassembles the subsequent operation as Spectrum-specific
/// </summary>
/// <param name="carryOn">
/// True, if the disassembler still remains in Spectrum-specific mode;
/// otherwise, false
/// </param>
/// <returns>Disassembled operation</returns>
private DisassemblyItem DisassembleSpectrumSpecificOperation(out bool carryOn)
{
if (_spectMode == SpectrumSpecificMode.None)
{
carryOn = false;
return(null);
}
DisassemblyItem item = null;
carryOn = false;
// --- Handle Spectrum 48 RST #08
if (_spectMode == SpectrumSpecificMode.Spectrum48Rst08)
{
// --- The next byte is the operation code
var address = (ushort)_offset;
var errorCode = Fetch();
_spectMode = SpectrumSpecificMode.None;
item = new DisassemblyItem(address)
{
Instruction = $".defb #{errorCode:X2}",
HardComment = $"(error code: #{errorCode:X2})",
LastAddress = (ushort)(_offset - 1)
};
}
// --- Handle Spectrum 48 RST #28
if (_spectMode == SpectrumSpecificMode.Spectrum48Rst28)
{
var address = (ushort)_offset;
var calcCode = Fetch();
item = DisassembleCalculatorEntry(address, calcCode, out carryOn);
}
// --- Handle Spectrum 128 RST #08
if (_spectMode == SpectrumSpecificMode.Spectrum128Rst8)
{
// --- The next byte is the operation code
var address = (ushort)_offset;
var callAddress = FetchWord();
_spectMode = SpectrumSpecificMode.None;
item = new DisassemblyItem(address)
{
Instruction = $".defw #{callAddress:X4}",
LastAddress = (ushort)(_offset - 1)
};
var provider = GetProvider <ISpectrum48RomLabelProvider>();
var label = provider?.GetSpectrum48Label(callAddress);
if (label != null)
{
item.HardComment = $"({label})";
}
}
if (!carryOn)
{
_spectMode = SpectrumSpecificMode.None;
}
return(item);
}
/// <summary>
/// Disassemble a calculator entry
/// </summary>
private DisassemblyItem DisassembleCalculatorEntry(ushort address, byte calcCode, out bool carryOn)
{
// --- Create the default disassembly item
var item = new DisassemblyItem(address)
{
LastAddress = (ushort)(_offset - 1),
Instruction = $".defb #{calcCode:X2}"
};
var opCodes = new List <byte> {
calcCode
};
carryOn = true;
// --- If we're in series mode, obtain the subsequent series value
if (_seriesCount > 0)
{
var lenght = (calcCode >> 6) + 1;
if ((calcCode & 0x3F) == 0)
{
lenght++;
}
for (var i = 0; i < lenght; i++)
{
var nextByte = Fetch();
opCodes.Add(nextByte);
}
item.Instruction = ".defb " + string.Join(", ", opCodes.Select(o => $"#{o:X2}"));
item.HardComment = $"({FloatNumber.FromCompactBytes(opCodes)})";
_seriesCount--;
return(item);
}
// --- Generate the output according the calculation op code
switch (calcCode)
{
case 0x00:
case 0x33:
case 0x35:
var jump = Fetch();
opCodes.Add(jump);
var jumpAddr = (ushort)(_offset - 1 + (sbyte)jump);
_output.CreateLabel(jumpAddr, null);
item.Instruction = $".defb #{calcCode:X2}, #{jump:X2}";
item.HardComment = $"({s_CalcOps[calcCode]}: {GetLabelName(jumpAddr)})";
carryOn = calcCode != 0x33;
break;
case 0x34:
_seriesCount = 1;
item.HardComment = "(stk-data)";
break;
case 0x38:
item.HardComment = "(end-calc)";
carryOn = false;
break;
case 0x86:
case 0x88:
case 0x8C:
_seriesCount = calcCode - 0x80;
item.HardComment = $"(series-0{calcCode-0x80:X1})";
break;
case 0xA0:
case 0xA1:
case 0xA2:
case 0xA3:
case 0xA4:
var constNo = calcCode - 0xA0;
item.HardComment = GetIndexedCalcOp(0x3F, constNo);
break;
case 0xC0:
case 0xC1:
case 0xC2:
case 0xC3:
case 0xC4:
case 0xC5:
var stNo = calcCode - 0xC0;
item.HardComment = GetIndexedCalcOp(0x40, stNo);
break;
case 0xE0:
case 0xE1:
case 0xE2:
case 0xE3:
case 0xE4:
case 0xE5:
var getNo = calcCode - 0xE0;
item.HardComment = GetIndexedCalcOp(0x41, getNo);
break;
default:
var comment = s_CalcOps.ContainsKey(calcCode)
? s_CalcOps[calcCode]
: $"calc code: #{calcCode:X2}";
item.HardComment = $"({comment})";
break;
}
return(item);
}
