ThermOS: An Energy Efficient Real-Time Operating System For An Ultra-low Power Embedded Device

A freely available RTOS was ported to the EnCore platform. It was then extended to include explicit deadlines and dynamic scheduling policies. Based on this, a number of Dynamic Voltage Scaling (DVS) policies were implemented and evaluated in terms of their energy savings and adherence to real-time performance. It was found that one policy (Look Ahead EDF) performed best when execution times were on average, well below their worst case time; while another policy (Hybrid Tianzhou) performed best when execution times were closer to their stated worst case. i Acknowledgements Many thanks to Professors Bjrn Franke and Nigel Topham, and everyone else in the Pasta Project, especially Oscar Almer, Igor Bhm, and Freddie Qu for their help and patience. ii Declaration I declare that this thesis was composed by myself, that the work contained herein is my own except where explicitly stated otherwise in the text, and that this work has not been submitted for any other degree or professional qualification except as specified.