Jumpstart: Fast Critical Service Resumption for a Partitioning Hypervisor in Embedded Systems

Complex embedded systems are now supporting the co-existence of multiple OSes to manage services once assigned to separate embedded microcontrollers. Automotive systems, for example, now use multiple OSes to consolidate electronic control unit (ECU) functions on a centralized embedded computing platform. Such platforms have the complexity of an industrial embedded PC, with multiple cores and hardware virtualization capabilities. This enables a partitioning hypervisor to spatially and temporally share the physical machine with separate guest OSes, which manage services of different criticality levels. However, PC-class hardware incurs a large latency to bootstrap an OS and associated application-level services. A firmware BIOS performs a power-on-self-test, and then loads OS images into memory from a bootable storage device. This latency is unacceptable in time-critical embedded systems, where important services must be operational within milliseconds of starting the system. In this paper, we present Jumpstart, a PC-class power management approach that minimizes the wakeup delay of a partitioning hypervisor for use in embedded systems. We show how Jumpstart resumes critical OS services and tasks from a low power suspended state in approximately 600 milliseconds, and reduces full system startup delay by a factor of 23. Additionally, Jumpstart consumes minimal power compared to approaches requiring a system boot from a previously powered-off state. By comparison, an alternative firmware-optimized bootloader, called Slim, reduces boot latency by a factor of 1.8.