Energy Macromodeling of Embedded Operating Systems

As embedded systems get more complex, deployment of embedded operating systems (OSs) as software run-time engines has become common. In particular, this trend is true even for batterypowered embedded systems, where maximizing battery life is a primary concern. In such OS-driven embedded software, the overall energy consumption depends very much on which OS is used and how the OS is used. Therefore, the energy effects of the OS need to be studied in order to design low-energy systems effectively. In this paper, we discuss the motivation for performing OS energy characterization and propose a methodology to perform the characterization systematically. The methodology consists of two parts. The first part is analysis, which is concerned with identifying a set of components that can be used to characterize the OS energy consumption, called energy characteristics. The second part is macromodeling, which is concerned with obtaining quantitative macromodels for the energy characteristics. It involves the process of experiment design, data collection, and macromodel fitting. The OS energy macromodels can be used conveniently as OS energy estimators in high-level or architectural optimization of embedded systems for low-energy consumption. As far as we know, this work is the first attempt to systematically tackle energy macromodeling of an embedded OS. To demonstrate our approach, we present experimental results for two wellknown embedded OSs, namely, iC/OS and embedded Linux OS.