private U8CodeBlock BuildBlock(int Address)
{
bool complete = false;
int offset = 0;
List <U8Cmd> Cmds = new List <U8Cmd>();
var newBlock = new U8CodeBlock(null);
while (!complete)
{
U8Cmd cmd = new U8Cmd();
offset += GetBlock(Address + offset, ref cmd, ref newBlock, ref complete);
Cmds.Add(cmd);
}
// save block
newBlock.Ops = Cmds.ToArray();
newBlock.Address = newBlock.Ops[0].Address;
this.Blocks.Add(newBlock);
return(newBlock);
}
private bool GetBlocks()
{
this.Blocks.Clear();
// Split all blocks based on branch conditions and terminate by return
// basically just check for anything thats capable of modifying the Instruction Pointer
// ALL Conditional relative branch instructions:
int ret = 2;
int AddrBlockStart = 0;
bool isEndOfBlock = false;
List <U8Cmd> Cmds = new List <U8Cmd>();
var newBlock = new U8CodeBlock(null);
// change to while;true loop?
//for (int i = 0; i < this.Disasm.Buffer.Length-6; i+= ret)
for (int i = 0x01000; i < this.Memory.Length - 6; i += ret) // dont kill the CPU
{
U8Cmd cmd = new U8Cmd();
ret = GetBlock(i, ref cmd, ref newBlock, ref isEndOfBlock);
cmd.Address = i;
Cmds.Add(cmd);
if (isEndOfBlock)
{
// save block
newBlock.Ops = Cmds.ToArray();
newBlock.Address = newBlock.Ops[0].Address;
this.Blocks.Add(newBlock);
Cmds.Clear();
newBlock = new U8CodeBlock(null);
isEndOfBlock = false;
}
}
// TODO: Replace with BuildBlock()
return(true);
}
// disassembles with block propertys
private int GetBlock(int Address, ref U8Cmd Cmd, ref U8CodeBlock newBlock, ref bool isEndOfBlock)
{
// ALL Conditional relative branch instructions:
int ret = -1;
byte[] buf = new byte[6];
if (Address + 6 > this.Memory.Length)
{
isEndOfBlock = true; // wont come back again
return(-1); // Cia Adios
}
// fill temp buff
for (int b = 0; b < buf.Length; b++)
{
buf[b] = this.Memory[Address + b];
}
// get opcode
//u8_cmd opcode = new u8_cmd();
ret = U8Decoder.DecodeOpcode(buf, ref Cmd);
Cmd.Address = Address;// dafuq???
//Cmds.Add(opcode);
// check branches
switch ((U8_OP)Cmd.Type)
{
case U8_OP.BGE_RAD: // conditional branch
case U8_OP.BLT_RAD:
case U8_OP.BGT_RAD:
case U8_OP.BLE_RAD:
case U8_OP.BGES_RAD:
case U8_OP.BLTS_RAD:
case U8_OP.BGTS_RAD:
case U8_OP.BLES_RAD:
case U8_OP.BNE_RAD:
case U8_OP.BEQ_RAD:
case U8_OP.BNV_RAD:
case U8_OP.BOV_RAD:
case U8_OP.BPS_RAD:
case U8_OP.BNS_RAD:
case U8_OP.BAL_RAD:
// if cond ? radr : PC+=2
// if op1 < 0 then negative else positive;
// conditions? dont care actually ;D
newBlock.JumpsToBlock = Cmd.Address + Cmd.Op1; // takes jump
newBlock.NextBlock = Cmd.Address + 2; // continue
isEndOfBlock = true;
break;
case U8_OP.B_AD: // branch
// PC = cadr[15:0] (op1) + second word
newBlock.NextBlock = (Cmd.Op1 * 0x10000) + Cmd.sWord; // takes jump
newBlock.JumpsToBlock = -1; // newBlock.JumpsToBlock; // dont set so we know its forced?
isEndOfBlock = true;
break;
//// NOTE: Just ignore them?
//case U8Decoder.U8_BL_AD: // caller address
// newBlock.NextBlock = Cmd.Address + 4; // len 2
// newBlock.JumpsToBlock = -1;
// isEndOfBlock = true;
// break;
//case U8Decoder.U8_BL_ER: // caller register ER
// newBlock.NextBlock = Cmd.Address + 2; ; // len 1
// newBlock.JumpsToBlock = -1;
// isEndOfBlock = true;
// break;
case U8_OP.B_ER:
// this jumps to ER? whats in ER?
newBlock.NextBlock = Cmd.Address += 2; // continue
isEndOfBlock = true;
break;
case U8_OP.RT: // return from subroutine?
isEndOfBlock = true; // there is no next ;D
break;
default:
break;
}
return(ret);
}
