FreeRTOS User Mode Scheduler for Mixed Critical Systems

FRANCISCO E. PAEZ; JOSE M. URRIZA; RICARDO CAYSSIALS; JAVIER D. OROZCO

Buenos Aires

Conferencia; 2015 Sixth Argentine Conference on Embedded Systems; 2015

ACSE

Real-time systems are applied in the more diverse applications. Most of these applications require specific configurations in order to meet their timing constraints. Realtime Operating Systems offer scheduling policies that  produce a certain behavior of the application, difficult to change in order to get a specific and desired dynamic of the system. On the other hand, most real-time applications include tasks with different real-time constraints: from hard real-time tasks to sporadic and soft real-time tasks. Configuring a real-time operating system to get the desire response for each one of these tasks generally involves a deep knowledge of the structure of the kernel and programming it in a privilege mode. In this paper, it is proposed an implementation of a user-level scheduler, easily configurable to adapt the dynamic of the system to the specific features of the application.