Custom Processing Unit - Tracing and Patching Intel Atom Microcode

Explore groundbreaking research on Intel Atom Microcode in this 28-minute Black Hat conference talk. Gain unprecedented insight into the internal workings of Intel CPUs through a systematic study and software-only framework for observing, tracing, and patching microcode execution. Learn about the development of a Ghidra decompiler for Atom Microcode and the reverse-engineering of CPU control register bus usage. Discover how undocumented instructions are leveraged to create a framework for complete control over CPU microcode. Examine the framework's capabilities in assembling and patching micro-instructions, hooking CPU events, and tracing microcode execution. Delve into the reverse-engineering of Intel CPU microcode update routines, uncovering the decryption algorithms and binary format of updates. Understand the surprising revelation that microcode updates are interpreted by the CPU as a custom language. Access the open-source framework and presentation materials for further exploration of this cutting-edge research by Pietro Borrello and Martin Schwarzl.