Accurate energy characterization of OS services in embedded systems

As technology scales for increased circuit density and performance, the management of power consumption in embedded systems is becoming critical. Because the operating system (OS) is a basic component of the embedded system, the reduction and characterization of its energy consumption is a main challenge for the designers. In this work, a flow of low power OS energy characterization is introduced. The variation of the energy and power consumption of the embedded OS services is studied. The remainder of this article details the methods used to determine energy and power overheads of a set of basic services of the embedded OS: scheduling, context switch and inter-process communication. The impacts of hardware and software parameters like processor frequency and scheduling policy on the energy consumption are analyzed. Also, models and laws of the power and energy are extracted. Then, to quantify the low power OS energetic overhead, the obtained models are integrated in the system level design. Our method allows estimating the energy consumption of the low power OS services when running an application on a specific hardware platform.