public static uint get_instruction(out INSTRUCTION inst, byte[] dat, uint idx, Mode mode)
{
INST ptr = null;
uint index = 0;
uint flags = 0;
inst = new INSTRUCTION();
get_real_instruction(dat, idx, ref index, ref flags);
if (Macros.MASK_EXT(flags) == 0)
{
inst.opcode = dat[idx + index];
ptr = opcode_tables.inst_table1[inst.opcode];
}
else if (Macros.MASK_EXT(flags) == Consts.EXT_CP)
{
if (dat[idx + index] < 0xc0)
{
index--;
inst.fpuindex = dat[idx + index] - 0xd8;
inst.opcode = dat[idx + index + 1];
ptr = opcode_tables.inst_table4[inst.fpuindex][Macros.MASK_MODRM_REG(inst.opcode)];
}
else
{
inst.fpuindex = dat[idx + index - 1] - 0xd8;
inst.opcode = dat[idx + index];
ptr = opcode_tables.inst_table4[inst.fpuindex][inst.opcode - 0xb8];
}
}
else if (Macros.MASK_EXT(flags) == Consts.EXT_T2)
{
inst.opcode = dat[idx + index];
get_real_instruction2(dat[idx + index], ref flags);
ptr = opcode_tables.inst_table2[inst.opcode];
if (Macros.MASK_TYPE_FLAGS((uint)ptr.type) == Consts.TYPE_3)
{
if (Macros.MASK_PREFIX_OPERAND(flags) == 1)
{
ptr = opcode_tables.inst_table3_66[inst.opcode];
}
else if (Macros.MASK_PREFIX_G1(flags) == 2)
{
ptr = opcode_tables.inst_table3_f2[inst.opcode];
}
else if (Macros.MASK_PREFIX_G1(flags) == 3)
{
ptr = opcode_tables.inst_table3_f3[inst.opcode];
}
}
}
if (Macros.MASK_EXT(flags) != 0 && (Macros.MASK_EXT(flags) < Consts.EXT_T2))
{
inst.opcode = dat[idx + index];
inst.extindex = Macros.MASK_MODRM_REG(dat[idx + index + 1]);
switch (Macros.MASK_EXT(flags))
{
case Consts.EXT_GC:
if (Macros.MASK_PREFIX_OPERAND(flags) == 1)
{
ptr = opcode_tables.inst_table_ext12_66[inst.extindex];
}
else
{
ptr = opcode_tables.inst_table_ext12[inst.extindex];
}
break;
case Consts.EXT_GD:
if (Macros.MASK_PREFIX_OPERAND(flags) == 1)
{
ptr = opcode_tables.inst_table_ext13_66[inst.extindex];
}
else
{
ptr = opcode_tables.inst_table_ext13[inst.extindex];
}
break;
case Consts.EXT_GE:
if (Macros.MASK_PREFIX_OPERAND(flags) == 1)
{
ptr = opcode_tables.inst_table_ext14_66[inst.extindex];
}
else
{
ptr = opcode_tables.inst_table_ext14[inst.extindex];
}
break;
case Consts.EXT_G7:
if (Macros.MASK_MODRM_MOD(dat[idx + index + 1]) == 3)
{
if (inst.extindex != 1)
{
return(0);
}
if (Macros.MASK_MODRM_RM(dat[idx + index + 1]) == 0)
{
ptr = opcode_tables.inst_monitor;
index++;
}
else if (Macros.MASK_MODRM_RM(dat[idx + index + 1]) == 1)
{
ptr = opcode_tables.inst_mwait;
index++;
}
else
{
return(0);
}
}
else
{
ptr = opcode_tables.inst_table_ext7[inst.extindex];
}
break;
default:
ptr = opcode_tables.inst_table_ext[(Macros.MASK_EXT(flags)) - 1][inst.extindex];
break;
}
}
index++;
if (ptr == null)
{
return(0);
}
if (ptr.mnemonic == null)
{
return(0);
}
if (ptr.modrm)
{
inst.modrm_offset = index;
}
inst.type = (InstructionType)Macros.MASK_TYPE_VALUE((uint)ptr.type);
inst.eflags_affected = ptr.eflags_affected;
inst.eflags_used = ptr.eflags_used;
inst.ptr = ptr;
if (!get_operand(ptr, ptr.flags1, inst, out inst.op1, dat, index + idx, mode, flags))
{
return(0);
}
if (!get_operand(ptr, ptr.flags2, inst, out inst.op2, dat, index + idx, mode, flags))
{
return(0);
}
if (!get_operand(ptr, ptr.flags3, inst, out inst.op3, dat, index + idx, mode, flags))
{
return(0);
}
inst.iop_read = ptr.iop_read;
inst.iop_written = ptr.iop_written;
inst.length += index + inst.immbytes + inst.dispbytes;
inst.mode = mode;
inst.flags = flags;
return(inst.length);
}
private static bool get_operand(INST inst, uint oflags, INSTRUCTION instruction, out OPERAND op, byte[] data, uint idx, Mode mode, uint iflags)
{
uint index = 0;
bool sib = false;
uint scale = 0;
uint reg = Consts.REG_NOP;
uint basereg = Consts.REG_NOP;
uint indexreg = Consts.REG_NOP;
uint dispbytes = 0;
Mode pmode;
op = new OPERAND();
if (oflags == Consts.FLAGS_NONE)
{
op.type = OperandType.OPERAND_TYPE_NONE;
return(true);
}
op.flags = oflags;
op.reg = Consts.REG_NOP;
op.basereg = Consts.REG_NOP;
op.indexreg = Consts.REG_NOP;
op.dispoffset = 0;
op.immoffset = 0;
if (inst.modrm)
{
pmode = MODE_CHECK_ADDR(mode, iflags);
if (instruction.length == 0)
{
instruction.modrm = (byte)idx;
instruction.length += 1;
}
reg = Macros.MASK_MODRM_REG(data[idx]);
if (Macros.MASK_MODRM_MOD(data[idx]) == 0)
{
if ((pmode == Mode.MODE_32) && (Macros.MASK_MODRM_RM(data[idx]) == Consts.REG_EBP))
{
dispbytes = 4;
}
if ((pmode == Mode.MODE_16) && (Macros.MASK_MODRM_RM(data[idx]) == Consts.REG_ESI))
{
dispbytes = 2;
}
}
else if (Macros.MASK_MODRM_MOD(data[idx]) == 1)
{
dispbytes = 1;
}
else if (Macros.MASK_MODRM_MOD(data[idx]) == 2)
{
dispbytes = (pmode == Mode.MODE_32) ? 4U : 2U;
}
if (pmode == Mode.MODE_32)
{
if ((Macros.MASK_MODRM_RM(data[idx]) == Consts.REG_ESP) && (Macros.MASK_MODRM_MOD(data[idx]) != 3))
{
sib = true;
instruction.sib = data[idx + 1];
if (instruction.length == 1)
{
instruction.sib = data[idx + 1];
instruction.length += 1;
}
basereg = Macros.MASK_SIB_BASE(data[idx + 1]);
indexreg = Macros.MASK_SIB_INDEX(data[idx + 1]);
scale = Macros.MASK_SIB_SCALE(data[idx + 1]) * 2;
if (scale == 6)
{
scale += 2;
}
if ((basereg == Consts.REG_EBP) && Macros.MASK_MODRM_MOD(data[idx]) == 0)
{
basereg = Consts.REG_NOP;
dispbytes = 4;
}
if (indexreg == Consts.REG_ESP)
{
indexreg = Consts.REG_NOP;
}
}
else
{
if (Macros.MASK_MODRM_MOD(data[idx]) == 0 && (Macros.MASK_MODRM_RM(data[idx]) == Consts.REG_EBP))
{
basereg = Consts.REG_NOP;
}
else
{
basereg = Macros.MASK_MODRM_RM(data[idx]);
}
}
}
else
{
switch (Macros.MASK_MODRM_RM(data[idx]))
{
case 0:
basereg = Consts.REG_EBX;
indexreg = Consts.REG_ESI;
break;
case 1:
basereg = Consts.REG_EBX;
indexreg = Consts.REG_EDI;
break;
case 2:
basereg = Consts.REG_EBP;
indexreg = Consts.REG_ESI;
break;
case 3:
basereg = Consts.REG_EBP;
indexreg = Consts.REG_EDI;
break;
case 4:
basereg = Consts.REG_ESI;
indexreg = Consts.REG_NOP;
break;
case 5:
basereg = Consts.REG_EDI;
indexreg = Consts.REG_NOP;
break;
case 6:
if (Macros.MASK_MODRM_MOD(data[idx]) == 0)
{
basereg = Consts.REG_NOP;
}
else
{
basereg = Consts.REG_EBP;
}
indexreg = Consts.REG_NOP;
break;
case 7:
basereg = Consts.REG_EBX;
indexreg = Consts.REG_NOP;
break;
}
if (Macros.MASK_MODRM_MOD(data[idx]) == 3)
{
basereg = Macros.MASK_MODRM_RM(data[idx]);
indexreg = Consts.REG_NOP;
}
}
}
switch (Macros.MASK_AM(oflags))
{
case Consts.AM_REG:
op.type = OperandType.OPERAND_TYPE_REGISTER;
op.reg = Macros.MASK_REG(oflags);
break;
case Consts.AM_IND:
op.type = OperandType.OPERAND_TYPE_MEMORY;
op.basereg = Macros.MASK_REG(oflags);
break;
case Consts.AM_M:
if (Macros.MASK_MODRM_MOD(data[idx]) == 3)
{
return(false);
}
goto skip_rest;
case Consts.AM_R:
if (Macros.MASK_MODRM_MOD(data[idx]) != 3)
{
return(false);
}
goto skip_rest;
case Consts.AM_Q:
case Consts.AM_W:
case Consts.AM_E:
skip_rest:
op.type = OperandType.OPERAND_TYPE_MEMORY;
op.dispbytes = dispbytes;
instruction.dispbytes = dispbytes;
op.basereg = basereg;
op.indexreg = indexreg;
op.scale = scale;
index = (sib) ? 1U : 0U;
if (dispbytes != 0)
{
op.dispoffset = index + 1 + idx;
}
switch (dispbytes)
{
case 0:
break;
case 1:
op.displacement = Macros.FETCH8(data, idx + 1 + index);
if (op.displacement >= 0x80)
{
op.displacement |= 0xffffff00;
}
break;
case 2:
op.displacement = Macros.FETCH16(data, idx + 1 + index);
break;
case 4:
op.displacement = Macros.FETCH32(data, idx + 1 + index);
break;
}
if ((basereg != Consts.REG_NOP) && (Macros.MASK_MODRM_MOD(data[idx]) == 3))
{
op.type = OperandType.OPERAND_TYPE_REGISTER;
op.reg = basereg;
}
break;
case Consts.AM_I1:
op.type = OperandType.OPERAND_TYPE_IMMEDIATE;
op.immbytes = 1;
op.immediate = 1;
break;
case Consts.AM_J:
op.type = OperandType.OPERAND_TYPE_IMMEDIATE;
oflags |= Consts.F_s;
goto am_i;
case Consts.AM_I:
am_i:
op.type = OperandType.OPERAND_TYPE_IMMEDIATE;
index = (inst.modrm) ? 1U : 0U;
index += (sib) ? 1U : 0U;
index += instruction.immbytes;
index += instruction.dispbytes;
op.immoffset = index + idx;
mode = MODE_CHECK_OPERAND(mode, iflags);
switch (Macros.MASK_OT(oflags))
{
case Consts.OT_b:
op.immbytes = 1;
op.immediate = Macros.FETCH8(data, idx + index);
if ((op.immediate >= 0x80) && (Macros.MASK_FLAGS(oflags) == Consts.F_s))
{
op.immediate |= 0xffffff00;
}
break;
case Consts.OT_v:
op.immbytes = (mode == Mode.MODE_32) ? 4U : 2U;
op.immediate = (mode == Mode.MODE_32) ? Macros.FETCH32(data, idx + index) : Macros.FETCH16(data, idx + index);
break;
case Consts.OT_w:
op.immbytes = 2;
op.immediate = Macros.FETCH16(data, idx + index);
break;
}
instruction.immbytes += op.immbytes;
break;
case Consts.AM_A:
op.type = OperandType.OPERAND_TYPE_IMMEDIATE;
mode = MODE_CHECK_OPERAND(mode, iflags);
op.dispbytes = (mode == Mode.MODE_32) ? 6U : 4U;
op.displacement = (mode == Mode.MODE_32) ? Macros.FETCH32(data, idx) : Macros.FETCH16(data, idx);
op.section = Macros.FETCH16(data, idx + op.dispbytes - 2);
instruction.dispbytes = op.dispbytes;
instruction.sectionbytes = 2;
break;
case Consts.AM_O:
op.type = OperandType.OPERAND_TYPE_MEMORY;
switch (Macros.MASK_OT(oflags))
{
case Consts.OT_b:
op.dispbytes = 1;
op.displacement = Macros.FETCH8(data, idx);
break;
case Consts.OT_v:
op.dispbytes = (mode == Mode.MODE_32) ? 4U : 2U;
op.displacement = (mode == Mode.MODE_32) ? Macros.FETCH32(data, idx) : Macros.FETCH16(data, idx);
break;
}
instruction.dispbytes = op.dispbytes;
op.dispoffset = idx;
break;
case Consts.AM_G:
op.type = OperandType.OPERAND_TYPE_REGISTER;
op.reg = reg;
break;
case Consts.AM_C:
case Consts.AM_D:
case Consts.AM_S:
case Consts.AM_T:
case Consts.AM_P:
case Consts.AM_V:
op.type = OperandType.OPERAND_TYPE_REGISTER;
op.reg = Macros.MASK_MODRM_REG(instruction.modrm);
break;
}
return(true);
}
