private static string decodeMoveControlToFromCoprocessorOperation(string opcode, uint operation)
{
GP_REGISTER rt = (GP_REGISTER)((operation >> 16) & 0x1F);
byte rd = (byte)((operation >> 11) & 0x1F);
return(opcode + " " + getGRPRegName(rt) + ", $v" + rd);
}
private static string decodeBranchOperation(string opcode, uint operation, uint address)
{
GP_REGISTER src = (GP_REGISTER)((operation >> 21) & 0x1F);
short imm = (short)((operation & 0xFFFF) << 2);
uint current_offset = (uint)((address + 4) + imm);
return(opcode + " " + getGRPRegName(src) + ", 0x" + (current_offset).ToString("X8"));
}
private static string decodeSpecialShiftOperation(string opcode, uint operation)
{
GP_REGISTER dest = (GP_REGISTER)((operation >> 11) & 0x1F);
GP_REGISTER src = (GP_REGISTER)((operation >> 16) & 0x1F);
int imm = (int)((operation >> 6) & 0x1F);
return(opcode + " " + getGRPRegName(dest) + ", " + getGRPRegName(src) + ", " + imm);
}
private static string decodeBranchEqualsOperation(string opcode, uint operation, uint address)
{
GP_REGISTER src1 = (GP_REGISTER)((operation >> 21) & 0x1F);
GP_REGISTER src2 = (GP_REGISTER)((operation >> 16) & 0x1F);
short imm = (short)((operation & 0xFFFF) << 2);
//Console.WriteLine("("+address.ToString("X8")+")immediate = " + imm);
uint current_offset = (uint)((address + 4) + imm);
return(opcode + " " + getGRPRegName(src1) + ", " + getGRPRegName(src2) + ", 0x" + current_offset.ToString("X8"));
}
private static string getGRPRegName(GP_REGISTER reg)
{
if (usingRegNames)
{
return(reg.ToString());
}
else
{
return("r" + ((byte)reg).ToString());
}
}
private static string decodeThreeRegisterOperation(string opcode, uint operation, bool swapRT_RS)
{
GP_REGISTER dest = (GP_REGISTER)((operation >> 11) & 0x1F);
GP_REGISTER src1 = (GP_REGISTER)((operation >> 21) & 0x1F);
GP_REGISTER src2 = (GP_REGISTER)((operation >> 16) & 0x1F);
if (!swapRT_RS)
{
return(opcode + " " + getGRPRegName(dest) + ", " + getGRPRegName(src1) + ", " + getGRPRegName(src2));
}
else
{
return(opcode + " " + getGRPRegName(dest) + ", " + getGRPRegName(src2) + ", " + getGRPRegName(src1));
}
}
private static string decodeTwoRegistersWithImmediateOperation(string opcode, uint operation)
{
GP_REGISTER dest = (GP_REGISTER)((operation >> 16) & 0x1F);
GP_REGISTER src = (GP_REGISTER)((operation >> 21) & 0x1F);
short imm = (short)(operation & 0xFFFF);
if (imm < 0)
{
return(opcode + " " + getGRPRegName(dest) + ", " + getGRPRegName(src) + ", -0x" + (-imm).ToString("X4"));
}
else
{
return(opcode + " " + getGRPRegName(dest) + ", " + getGRPRegName(src) + ", 0x" + imm.ToString("X4"));
}
}
private static string decodeNormalMIPSLoadStore(string opcode, uint operation)
{
GP_REGISTER dest = (GP_REGISTER)((operation >> 16) & 0x1F);
GP_REGISTER base_ = (GP_REGISTER)((operation >> 21) & 0x1F);
short imm = (short)(operation & 0xFFFF);
if (imm < 0)
{
opcode += " " + getGRPRegName(dest) + ", -0x" + (-imm).ToString("X4") + "(" + getGRPRegName(base_) + ")";
}
else
{
opcode += " " + getGRPRegName(dest) + ", 0x" + imm.ToString("X4") + "(" + getGRPRegName(base_) + ")";
}
return(opcode);
}
private static string decodeCOP0Operation(uint operation)
{
string str = "Unimplemented (COP0 operation)";
byte mt = (byte)((operation >> 21) & 0x1F);
GP_REGISTER rt = (GP_REGISTER)((operation >> 16) & 0x1F);
CP0_REGISTER rd = (CP0_REGISTER)((operation >> 11) & 0x1F);
switch (mt)
{
case 0x00: // MFC0
str = "mfc0 " + getGRPRegName(rt) + ", " + getCP0RegName(rd);
break;
case 0x04: // MTC0
str = "mtc0 " + getGRPRegName(rt) + ", " + getCP0RegName(rd);
break;
}
return(str);
}
public static string decodeOPERATION(uint operation, uint address, OPTIONS options)
{
if (operation == 0x00000000)
{
return("nop");
}
usingRegNames = options.HasFlag(OPTIONS.USE_GP_NAMES);
usingLongForm = options.HasFlag(OPTIONS.USE_LONG_FORM);
usingArmipsCP0Names = options.HasFlag(OPTIONS.USE_ARMIPS_CP0_NAMES);
RSP_OPCODE opcode = (RSP_OPCODE)((operation >> 26) & 0x3F);
string str = "Unimplemented (opcode: " + Convert.ToString((int)opcode, 2) + "b)";
switch (opcode)
{
case RSP_OPCODE.J:
case RSP_OPCODE.JAL:
str = opcode.ToString().ToLower() + " 0x0" + ((operation & 0x03FFFFFF) << 2).ToString("X7");
break;
case RSP_OPCODE.BEQ:
case RSP_OPCODE.BNE:
str = decodeBranchEqualsOperation(opcode.ToString().ToLower(), operation, address);
break;
case RSP_OPCODE.BLEZ:
case RSP_OPCODE.BGTZ:
str = decodeBranchOperation(opcode.ToString().ToLower(), operation, address);
break;
case RSP_OPCODE.ADDI:
case RSP_OPCODE.ADDIU:
case RSP_OPCODE.SLTI:
case RSP_OPCODE.SLTIU:
case RSP_OPCODE.ANDI:
case RSP_OPCODE.ORI:
case RSP_OPCODE.XORI:
str = decodeTwoRegistersWithImmediateOperation(opcode.ToString().ToLower(), operation);
break;
case RSP_OPCODE.LUI:
str = decodeOneRegisterWithImmediateOperation(opcode.ToString().ToLower(), operation);
break;
case RSP_OPCODE.COP0:
str = decodeCOP0Operation(operation);
break;
case RSP_OPCODE.COP2:
{
//str = "Vector operation!";
str = decodeCOP2Operation(operation);
}
break;
case RSP_OPCODE.LB:
case RSP_OPCODE.LH:
case RSP_OPCODE.LW:
case RSP_OPCODE.LBU:
case RSP_OPCODE.LHU:
case RSP_OPCODE.LWU:
case RSP_OPCODE.SB:
case RSP_OPCODE.SH:
case RSP_OPCODE.SW:
str = decodeNormalMIPSLoadStore(opcode.ToString().ToLower(), operation);
break;
case RSP_OPCODE.LWC2:
{
str = decodeLoadStoreOperation(operation, "l");
}
break;
case RSP_OPCODE.SWC2:
{
str = decodeLoadStoreOperation(operation, "s");
}
break;
case RSP_OPCODE.REGIMM:
{
byte subop = (byte)((operation >> 16) & 0x1F);
switch (subop)
{
case 0x00: // BLTZ operation
str = decodeBranchOperation("bltz", operation, address);
break;
case 0x01: // BGEZ operation
str = decodeBranchOperation("bgez", operation, address);
break;
case 0x10: // BLTZAL operation
str = decodeBranchOperation("bltzal", operation, address);
break;
case 0x11: // BGEZAL operation
str = decodeBranchOperation("bgezal", operation, address);
break;
}
}
break;
case RSP_OPCODE.SPECIAL:
{
byte subop = (byte)(operation & 0x3F);
switch (subop)
{
case 0x00: // SLL operation
str = decodeSpecialShiftOperation("sll", operation);
break;
case 0x02: // SRL operation
str = decodeSpecialShiftOperation("srl", operation);
break;
case 0x03: // SRA operation
str = decodeSpecialShiftOperation("sra", operation);
break;
case 0x04: // SLLV operation
str = decodeThreeRegisterOperation("sllv", operation, true);
break;
case 0x06: // SRLV operation
str = decodeThreeRegisterOperation("srlv", operation, true);
break;
case 0x07: // SRAV operation
str = decodeThreeRegisterOperation("srav", operation, true);
break;
case 0x08: // JR operation
str = "jr " + getGRPRegName(((GP_REGISTER)((operation >> 21) & 0x1F)));
break;
case 0x09: // JALR operation
{
GP_REGISTER return_reg = (GP_REGISTER)((operation >> 11) & 0x1F);
if (return_reg == GP_REGISTER.ra)
{
str = "jalr " + getGRPRegName(((GP_REGISTER)((operation >> 21) & 0x1F)));
}
else
{
str = "jalr " + getGRPRegName(return_reg) + ", " + getGRPRegName(((GP_REGISTER)((operation >> 21) & 0x1F)));
}
}
break;
case 0x0D: // BREAK operation
str = "break " + ((operation >> 6) & 0xFFFFF);
break;
case 0x20: // ADD operation
str = decodeThreeRegisterOperation("add", operation, false);
break;
case 0x21: // ADDU operation
str = decodeThreeRegisterOperation("addu", operation, false);
break;
case 0x22: // SUB operation
str = decodeThreeRegisterOperation("sub", operation, false);
break;
case 0x23: // SUBU operation
str = decodeThreeRegisterOperation("subu", operation, false);
break;
case 0x24: // AND operation
str = decodeThreeRegisterOperation("and", operation, false);
break;
case 0x25: // OR operation
str = decodeThreeRegisterOperation("or", operation, false);
break;
case 0x26: // XOR operation
str = decodeThreeRegisterOperation("xor", operation, false);
break;
case 0x27: // NOR operation
str = decodeThreeRegisterOperation("nor", operation, false);
break;
case 0x2A: // SLT operation
str = decodeThreeRegisterOperation("slt", operation, false);
break;
case 0x2B: // SLTU operation
str = decodeThreeRegisterOperation("sltu", operation, false);
break;
default:
str = "Unimplemented (special: " + Convert.ToString(subop, 2) + "b)";
break;
}
}
break;
}
return(str);
}
private static string decodeOneRegisterWithImmediateOperation(string opcode, uint operation)
{
GP_REGISTER dest = (GP_REGISTER)((operation >> 16) & 0x1F);
return(opcode + " " + getGRPRegName(dest) + ", 0x" + (operation & 0xFFFF).ToString("X4"));
}
