Decoding i386 opcodes to instructions

Question

I'm trying to Is there any good resource available to learn 'decoding' of i386 opcodes? Most of the websites talk about how to encode instructions, but I don't find anywhere something telling as to how to decode opcodes to instructions.

I've looked at the source code of some disassemblers, but I want some documentation as to how to decode opcodes to instructions.

Thanks and Regards,
Hrishikesh Murali

Answer 1

Read the processor manuals, they have it described, though maybe not in complete details:

1. Intel Manuals, in particular see Chapter 2 in Volume 2A and Appendix A in Volume 2B.
2. AMD Manuals, see Programmer's Manual Volume 3.

See also How to interpret the opcode manually?