The impact of operating system adoption in an embedded project: A case study

The use of an operating system (OS) is advocated as a means to simplify software development, freeing programmers from managing low-level hardware and providing a simpler programming interface for common tasks. The high complexity of modern desktop computers makes an OS indispensable; embedded systems, on the other hand, are limited architectures, usually severely cost- and power-constrained. Because of the additional demands imposed by an OS, embedded developers are faced with the crucial decision of whether to adopt an OS or not. In this paper, we present a case study in which a sample application (an embedded weather station) was developed under three different scenarios: without any OS, using the μC/OS-II real-time OS, and using the uClinux general-purpose OS. An FPGA and an SoPC were used to provide a flexible hardware platform able to accommodate all three configurations. The adoption of an OS provided a reduction of up to 48% in development time; on the other hand, it increased program memory requirements in at least 71%.