Speakers: Benjamin Kollenda, Philipp Koppe An introduction into reverse-engineering x86 microcode and writing it yourself Microcode is an abstraction layer on top of the physical components of a CPU and present in most general-purpose CPUs today. While it is well-known that CPUs feature a microcode update mechanism, very little is known about its inner workings given that microcode and the update mechanism itself are proprietary and have not been throughly analyzed yet. We close this gap by both analyzing microcode and writing our own programs for it. This talk will give an insight into our results and how we achieved them, including live demos of what we can do and technical details.