This blogpost explains how we recovered the firmware of a fleet-sharing Electronic Control Unit (ECU) which has been erased from a FAT memory using Capstone disassembler to locate scattered parts, to be able to reverse-engineer it.

Analyzing an automotive ECU firmware is sometimes quite challenging, especially when you cannot emulate some of its most interesting functions to find vulnerabilities, like ECUs based on Renesas RH850 system-on-chips. This article details how we managed to add support for this specific architecture into Unicorn Engine, the various challenges we faced and how we successfully used this work to emulate and analyze a specific function during an assignment.