CheriRTOS: A Capability Model for Embedded Devices

  • Hongyan Xia ,
  • Jonathan Woodruff ,
  • Hadrien Barral ,
  • Lawrence Esswood ,
  • Alexandre Joannou ,
  • Robert Kovacsics ,
  • David Chisnall ,
  • Michael Roe ,
  • Brooks Davis ,
  • Edward Napierala ,
  • John Baldwin ,
  • Khilan Gudka ,
  • Peter G. Neumann ,
  • Alex Richardson ,
  • Simon W. Moore ,
  • Robert N. M. Watson

Proceedings of the 2018 IEEE 36th International Conference on Computer Design (ICCD) |

Organized by IEEE

—Embedded systems are deployed ubiquitously among various sectors including automotive, medical, robotics and avionics. As these devices become increasingly connected, the attack surface also increases tremendously; new mechanisms must be deployed to defend against more sophisticated attacks while not violating resource constraints. In this paper we present
CheriRTOS on CHERI-64, a hardware-software platform atop Capability Hardware Enhanced RISC Instructions (CHERI) for embedded systems.

Our system provides efficient and scalable task isolation, fast and secure inter-task communication, fine-grained memory safety, and real-time guarantees, using hardware capabilities as the sole protection mechanism. We summarize state-of-the-art security and memory safety for embedded systems for comparison with our platform, illustrating the superior substrate provided by CHERI’s capabilities. Finally, our evaluations show that a capability system can be implemented within the constraints of embedded systems.