Description

This is an old side project. An x86/x64 machine code decoder. It is useful to get instructions' length and identify each of its fields.

Example:

C7 85 68 FF FF FF 00 00 00 00

This is the instruction:

MOV DWORD PTR SS:[LOCAL.38],0

What follows are some of the information collected by the disassembler, based on the specific instruction:

RAW bytes (hex): C7 85 68 FF FF FF 00 00 00 00
Instr. length: 10
Print instruction fields:
        Located Prefixes 0:

        OP: 0xC7
        mod_reg_rm: 0x85
        disp (4): 0xFFFFFF68
        Iimm: 0x0

Lacks the mnemonic representation: from the previous machine code is not able to produce the "MOV..." instruction, for example.

Goals

The goal is almost easy: partially implement the mnemonic representation. I have already started during the weekend, likely tomorrow I will push the branch!

Resources

• The project: https://github.com/DispatchCode/x64-Instruction-Decoder/
• This is useful to avoid gdb and objdump in local: https://defuse.ca/online-x86-assembler.htm
• Another interesting resource is https://godbolt.org/