Open IoT & ELC 2017

The partitioning hypervisor Jaihouse allows us to run safety critical and uncritical applications in parallel on a single SoC. We present our experiences when porting a safety and real-time critical existing application as a Jailhouse guest. It shows a novel and promising approach for implementing mixed-criticality applications with real-time requirement while not loosing the benefits of Linux. This is done by static partitioning of hardware resources; guests do not interfere.
We will present a multicopter platform running the real-time critical flight stack in an isolated Jailhouse guest. This proves the practicability of Jailhouse as well as the suitability for real-time safety critical systems by porting an existing application to a Jailhouse cell. We stress its concept and show up current hardware limitations, like undesired behaviour and present possible workarounds and solutions.

The Linux kernel trace event subsystem provides a large array of tracepoints (and an infinite number of others can be added dynamically) which are used by various tracing utilities both inside and outside the kernel. Unless one-off external logic (code) is applied, there's no way to extract inter-event quantities such as latencies from the trace subsystem itself, even though the data to do that is already trivially there. This talk introduces a general-purpose mechanism for extracting inter-event values from arbitrary sets of events and shows how both one-off/one-line/programming-free experiments and higher-level tools such as latency histograms can be built on top of it.