RT-SHADOWS: Real-time system hardware for agnostic and deterministic OSes within softcore

Multithreading is a key feature for dealing with the complexity of current generation embedded devices. Real-Time Operating Systems (RTOSes) provide a higher level of abstraction that alleviates design complexity and time-to-market pressure, inducing, however, undesired latencies and unpredictable execution times. Research works have been focusing on improving performance, determinism or agnosticism, but none simultaneously tackled the three metrics. This work in progress paper presents RT-SHADOWS, a co-designed architecture that promotes configurability, determinism and agnosticism from the outset. A multi-thread ARM softcore processor was exploited and extended by offloading the scheduling-related features into the hardware layer. The hardware multi-thread support is transparent for the standard RTOS applications and independent of the Operating System (OS). Promising preliminary results demonstrate huge improvements on performance and determinism, with only a small cost on hardware.