Old New Things: An Examination of the Philips TriMedia Architecture presented at ekopartySecurityConference 2018

by Nahuel Riva,

Summary : In today’s Intel/AMD and ARM controlled world, it’s always interesting, for a reverse engineer, to find new or uncommon CPU architectures to learn and play with. It’s always a challenge to deal with uncommon/unknown firmware files and weird file formats and try to unravel what’s behind. This allows us to continuously improve and expand our knowledge. If you are willing to learn new stuff, this talk is for you. In this presentation, by inspecting an IoT device, you will see an examination of the architectural and functional aspects of the Philips TriMedia architecture, an ‘obscure’ CPU that makes you think you are in the darkest corner of the reverse engineering (RE) world. You’ll see some characteristics of the architecture itself and the inner workings of the CPU, its assembly language (instruction set, encoding and decoding), and the toolset available at the moment to work with this architecture. Also, you’ll learn some general aspects related to the RE methods used to deal with an unknown/uncommon architecture like Philips TriMedia.