Affordable Separation on Embedded Platforms: Soft Reboot Enabled Virtualization on a Dual Mode System

While security has become important in embedded systems, commodity operating systems often fail in effectively separating processes, mainly due to a too large trusted computing base. System virtualization can establish isolation already with a small code base, but many existing embedded CPU architectures have very limited virtualization hardware support, so that the performance impact is often non-negligible. Targeting both security and performance, we investigate an approach in which a few minor hardware additions together with virtualization offer protected execution in embedded systems while still allowing non-virtualized execution when secure services are not needed. Benchmarks of a prototype implementation on an emulated ARM Cortex A8 platform confirm that switching between those two execution forms can be done efficiently