Awkernel: RTOS Bridging DAG Scheduling Theory and Component-Oriented Real-Time Systems Practice
This study addresses the lack of real hardware support in DAG scheduling theory and the difficulty existing platforms face in ensuring timing analyzability. To this end, we propose the first open-source RTOS that natively supports real-time DAG scheduling. By introducing a Function-as-Subtask (FasS) API to enforce DAG semantics and integrating a publish/subscribe model with a Global Earliest Deadline First (GEDF) algorithm, the system achieves OS-level native support for DAG task models alongside a modular scheduler with microsecond-level overhead and an automated testbed. Raspberry Pi-based experiments demonstrate that a GEDF scheduler implemented in merely 226 lines of code successfully ports autonomous driving components, enabling mechanical port migration without additional constraint reasoning. This work effectively bridges the gap between theoretical scheduling frameworks and practical engineering implementation.