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 nonnegligible. 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.