Asymmetric Virtualisation for Real-Time Systems

The steady increase in performance of the processors commonly adopted for real-time systems leads to the opportunity of hosting diverse classes of tasks on the same hardware, for example real-time control tasks and a man-machine interface, each one under the control of its own operating system. This paper describes how an asymmetric virtualisation layer has been realised on top of the ARM TrustZone security extension, in order to support the concurrent execution of both a real-time and a general purpose operating system on the same processor. The resulting implementation has a small execution time overhead and does not require any modification to the general purpose operating system.