private uint ExecuteARMInstruction(uint opcode, out bool swiInstruction)
{
swiInstruction = false;
// Check if this op does not have a condition prefix
if ((opcode & 0xF0000000) == 0xF0000000)
{
// It must be BLX(1) or an undefined instruction
if ((opcode & 0xFE000000) == 0xFE000000)
{
return(blx1(opcode));
}
return(DefaultInvalidOpCodeHandler(opcode));
}
//Check condition code and execute it if the condition code allows
if (!check_cc((byte)(opcode >> 28)))
{
return(1);
}
SWIFlag = false;
uint cycleCount = ARMInstructionRegistry[opcode](opcode);
swiInstruction = SWIFlag;
return(cycleCount);
}//ExecuteARMInstruction
private void RegisterARMInstructions()
{
ARMInstructionRegistry = new PlainARMInstructionRegistry();
//The opcodes are broken into groups roughly corresponding to the table
//in ARMv7 A5.1
//Data ops
RegisterARMDataOps();
//Load/Store ops (also some extra load/store ops from the Data Ops section like LDRH)
RegisterARMLoadStoreOps();
//Multiple Load/Store (just LDM and STM and their variants)
RegisterOpcode(0x08100000, 0xf1efffff, ldm, "LDM");
RegisterOpcode(0x08000000, 0xf1efffff, stm, "STM");
//Branch instructions (the handler is so simple that it's not worth breaking this group up)
RegisterOpcode(0x0a000000, 0xf1ffffff, branch, "branch");
//FP coprocessor - 110x xxxx xx
RegisterOpcode(0x0c000000, 0xf1ffffff, mFPP.Execute, "FPP (1)");
//FP coprocessor - 1110 xxxx xx
RegisterOpcode(0x0e000000, 0xf0ffffff, mFPP.Execute, "FPP (2)");
//Everything in the 1111 xxxx xx range counts as SWI (which, at this point, means
//"reserved for plugin").
RegisterOpcode(0x0f000000, 0xf0ffffff, delegate(uint opcode) { SWIFlag = true; return(0); }, "SWI");
}