New Reconfigurable Middleware for Feasible Adaptive RT-Linux

This paper is interested in reconfigurable real-time embedded OS for microprocessors. Our study concerns specifically RT-Linux. Since the latter is not designed to be reconfigurable, we propose to develop an intermediate layer to play the role of middleware that will be in interaction with the kernel Linux. This layer will manage the addition/removal/update of the periodic and also aperiodic tasks sharing resources and with precedence constraints. These tasks should respect their deadlines after any reconfiguration scenario. The proposed middleware will divide the hardware execution into several virtual processors as time slots. The decomposition is done based on the task’s category. The first virtual processor executes dependent periodic tasks, the second one executes dependent aperiodic tasks with hard deadlines and the third virtual processor executes dependent aperiodic tasks with soft deadlines. After applying a reconfiguration scenario, some tasks may miss their deadlines and the power consumption may increase. In order to re-obtain the feasibility of the system after a such scenario, an agent-based-architecture is defined to modify the parameters of the tasks. The different services offered by this middleware are developed. A simulation study is done in order to highlight the performance of our proposed solutions.