Libor Waszniowski CTU xwasznio@lab.felk.cut.cz Zdenek Hanzalek CTU hanzalek@rtime.felk.cvut.cz 2003 OCERA Consortium Real time, Operating system, Cooperative scheduling, Timed automata, Model checking This component is theoretical study offering methodology and tool support for model checking of real-time applications running under multitasking operating system. Theoretical background is based on timed automata by Allur and Dill. As this approach does not allow to model pre-emption we focus on cooperative scheduling. The cooperative scheduler under assumption performs rescheduling in specific points given by "yield" instruction in the application processes. In the addition, interrupt service routines are considered, and their enabling/disabling is controlled by interrupt server considering specified server capacity. The server capacity has influence on the margins of the computation times in the application processes. Such systems, used in practical real-time applications, can be modelled by timed automata and further verified by existing model checking tools. The approach is illustrated in the form of examples in the real-time verification tool UPPAAL.