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Support for Hierarchical Scheduling in FreeRTOS


Awarded IEEE-ies scholarship for this paper.

Publication Type:

Conference/Workshop Paper


16th IEEE International Conference on Emerging Technologies and Factory Automation




This paper presents the implementation of hierarchical scheduling framework HSF on an open source real-time operating system FreeRTOS to support the temporal isolation of a number of real-time components (or applications) on a single processor. The goal is to achieve predictable integration and reusability of independently developed components or tasks. It presents the initial results of the HSF implementation by running it on an AVR 32-bit board EVK1100. The paper addresses the fixed-priority preemptive scheduling at both global and local scheduling levels. It describes the detailed design of HSF with the emphasis of doing minimal changes to the underlying FreeRTOS kernel and keeping its API intact. Finally it provides (and compares) the results for the performance measures of periodic and deferrable servers with respect to the overhead of the implementation.


author = {Rafia Inam and Jukka M{\"a}ki-Turja and Mikael Sj{\"o}din and Mohammad Ashjaei and Sara Afshar},
title = {Support for Hierarchical Scheduling in FreeRTOS},
note = {Awarded IEEE-ies scholarship for this paper.},
month = {September},
year = {2011},
booktitle = {16th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA11)},
publisher = {IEEE},
url = {}