3. Role of operating systems in embedded systems

The role of an operating system, whether in a conventional computer system or in an embedded system, is to abstract hardware resources so that the application has a simplified view of them [3]. In practice, this translates into two different abstractions. The first concerns processors, for which the aim is to share computing power efficiently, according to various criteria which we'll come back to later. This sharing is achieved by means of a scheduler, which selects a given task at a given moment for immediate execution. The second concerns potentially shared access to peripheral devices, via drivers which, on the one hand, know how to configure and exchange data with the device and, on the other, guarantee access by a single task (so-called atomic access) if necessary.