Zentool: A Powerful Utility for AMD Zen Microcode Manipulation

Zentool is a suite of tools for analyzing, manipulating, and generating microcode patches for AMD Zen processors. It includes a frontend command `zentool`, a simple assembler `mcas`, and a disassembler `mcop`. You can inspect and modify various parts of a microcode file, such as the revision number, match registers, and instructions, even creating custom microcode patches. Root privileges are required to load microcode, and modifications need to be re-signed for validity. This tool builds on work by members of the Google Hardware Security Team, and is influenced by relevant books and papers.