private static bool ISP_4(uint uInstr, MilStd1750Disassembler dasm)
{
var imm = bf4_4.Read(uInstr) + 1u;
dasm.ops.Add(ImmediateOperand.Word16((ushort)imm));
return(true);
}
private static bool N(uint uInstr, MilStd1750Disassembler dasm)
{
var n = (ushort)bf4_4.Read(uInstr);
dasm.ops.Add(ImmediateOperand.Word16(n));
return(true);
}
/// <summary>
/// IC-relative
/// </summary>
private static bool ICR(uint uInstr, MilStd1750Disassembler dasm)
{
var disp = bf0_8.ReadSigned(uInstr);
var addrDst = dasm.addr + disp;
dasm.ops.Add(AddressOperand.Create(addrDst));
return(true);
}
/// <summary>
/// 16-bit immedate following the instruction word.
/// </summary>
private static bool IM(uint uInstr, MilStd1750Disassembler dasm)
{
if (!dasm.rdr.TryReadUInt16(out ushort imm))
{
return(false);
}
dasm.ops.Add(ImmediateOperand.Word16(imm));
return(true);
}
/// <summary>
/// XIO command decoder
/// </summary>
private static bool Xio(uint uInstr, MilStd1750Disassembler dasm)
{
if (!dasm.rdr.TryReadBeUInt16(out ushort cmd))
{
return(false);
}
var ra = Registers.GpRegs[bf4_4.Read(uInstr)];
switch (cmd >> 12)
{
case 0:
dasm.mnemonic = Mnemonic.xio_po;
dasm.ops.Add(new RegisterOperand(ra));
dasm.ops.Add(ImmediateOperand.Word16((ushort)(cmd & 0x03FF)));
return(true);
case 0x4:
switch (cmd)
{
case 0x4000:
dasm.mnemonic = Mnemonic.xio_co;
dasm.ops.Add(new RegisterOperand(ra));
return(true);
case 0x4001:
dasm.mnemonic = Mnemonic.xio_clc;
return(true);
}
break;
case 0xA:
switch (cmd)
{
case 0xAD51:
// 'MQ': Seems to be legit, but can't find documentation for it.
dasm.mnemonic = Mnemonic.xio_unknown;
dasm.ops.Add(ImmediateOperand.UInt16(cmd));
return(true);
}
break;
}
var testGenSvc = dasm.arch.Services.GetService <ITestGenerationService>();
testGenSvc?.ReportMissingDecoder("MS1750Dis", dasm.addr, dasm.rdr, $"xio {cmd:X4}");
return(false);
}
/// <summary>
/// Address or indexed address
/// </summary>
private static bool Ax(uint uInstr, MilStd1750Disassembler dasm)
{
if (!dasm.rdr.TryReadBeUInt16(out ushort imm))
{
return(false);
}
var ixReg = bf0_4.Read(uInstr);
if (ixReg != 0)
{
var op = new ImmediateOperand(Constant.Create(PrimitiveType.Word16, imm));
dasm.ops.Add(op);
var xReg = Registers.GpRegs[ixReg];
dasm.ops.Add(new RegisterOperand(xReg));
}
else
{
var op = AddressOperand.Ptr16(imm);
dasm.ops.Add(op);
}
return(true);
}
private static bool Imm8(uint uInstr, MilStd1750Disassembler dasm)
{
dasm.ops.Add(ImmediateOperand.Word16((ushort)bf0_8.Read(uInstr)));
return(true);
}