Modelagem e Implementação de Escalonadores de Tempo Real para Sistemas Embarcados
Resumo
Devido a suas características, sistemas embarcados freqüentemente demandam um projeto integrado de software e hardware com restrições de tempo real. Para que tais restrições sejam respeitadas, uma política de escalonamento de tarefas adequada deve ser selecionada. Este trabalho apresenta a modelagem e implementação de escalonadores de tempo real para sistemas embarcados, no contexto do projeto de sistemas orientados à aplicação. Esta abordagem permitiu a separação da política de escalonamento e seu mecanismo, promovendo uma maior reusabilidade dos artefatos envolvidos. Os resultados apresentados demonstram que esta implementação permite o seu uso em microcontroladores de 8 bits, arquiteturas de 32 bits, e até mesmo para implementações dedicadas de hardware.Referências
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Anderson, E., Agron, J., Peck, W., Stevens, J., Baijot, F., Komp, E., Sass, R., and Andrews, D. (2006). “Enabling a uniform programming model across the software/hardware boundary”. In Field-Programmable Custom Computing Machines, 2006. FCCM ’06. 14th Annual IEEE Symposium on, pages 89–98.
Buttazzo, G. (1997). Hard Real-Time Computing Systems. Kluwer Academic Publishers.
Fröhlich, A. A. (2001). Application-Oriented Operating Systems. PhD thesis, Sankt Augustin: GMD - Forschungszentrum Informationstechnik.
Fröhlich, A. A. and Schröeder-Preikschat, W. (2000). “Scenario adapters: Efficiently adapting components.” In Proceedings of 4th World Multiconference on Systemics, Cybernetics and Informatics, Orlando, USA.
G.C. Buttazzo, G. L. and Abeni, L. (1998). “Elastic task model for adaptive rate control.” In 19th IEEE Real-Time Systems Symposium, pages 286–295, Madrid, Spain.
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Kohout, P. and Jacob, B. (2003). “Hardware support for real-time operating systems.” In Proceedings of CODES - ISSS’03, Newport Beach, CA - USA.
Marcondes, H. and Fröhlich, A. A. M. (2008). “On hybrid hw/sw components for embedded system design.” In Proceedings of the 17th IFAC World Congress, 2008, volume 17, Seoul, South Korea. IFAC.
Mooney, V. and Micheli, G. D. (2000). “Hardware/software codesign of run-time schedulers for real-time systems.” In Proceedings of Design Automation of Embedded Systems, pages 89–144.
P. Kuacharoen, M. S. and Mooney, V. (2003). “A configurable hardware scheduler for real-time systems.” In Proceedings of International Conference on Engineering of Reconfigurable Systems and Algorithms - ERSA’03.
Polpeta, F. V. and Fröhlich, A. A. (2004). “Hardware mediators: a portability artifact for component-based systems.” In Proceedings of International Conference on Embedded and Ubiquitous Computing, volume 3207, pages 271–280.
Polpeta, F. V. and Fröhlich, A. A. (2005). “On the automatic generation of soc-based embedded systems.” In Proceedings of the 10th IEEE International Conference on Emerging Technologies and Factory Automation.
Shalan, M. and Mooney, V. (2000). “A dynamic memory management unit for embedded real-time system-on-a-chip.” In Proceedings of International Conference on Compilers, Architecture and Synthesis for Embedded Systems, pages 180–186.
Shark (2008). S.ha.r.k.: Soft hard real-time kernel. World Wide Web.
Wiedenhoft, G. R. and Fröhlich, A. A. (2008). “Gerência de energia no epos utilizando técnicas da computação imprecisa.” In Proceedings of the Fifth Brazilian Workshop on Operating Systems, pages 34–45.
Anderson, E., Agron, J., Peck, W., Stevens, J., Baijot, F., Komp, E., Sass, R., and Andrews, D. (2006). “Enabling a uniform programming model across the software/hardware boundary”. In Field-Programmable Custom Computing Machines, 2006. FCCM ’06. 14th Annual IEEE Symposium on, pages 89–98.
Buttazzo, G. (1997). Hard Real-Time Computing Systems. Kluwer Academic Publishers.
Fröhlich, A. A. (2001). Application-Oriented Operating Systems. PhD thesis, Sankt Augustin: GMD - Forschungszentrum Informationstechnik.
Fröhlich, A. A. and Schröeder-Preikschat, W. (2000). “Scenario adapters: Efficiently adapting components.” In Proceedings of 4th World Multiconference on Systemics, Cybernetics and Informatics, Orlando, USA.
G.C. Buttazzo, G. L. and Abeni, L. (1998). “Elastic task model for adaptive rate control.” In 19th IEEE Real-Time Systems Symposium, pages 286–295, Madrid, Spain.
Harvey DEITEL, Paul DEITEL, D. R. C. (2005). Sistemas operacionais. Prentice Hall.
Kohout, P. and Jacob, B. (2003). “Hardware support for real-time operating systems.” In Proceedings of CODES - ISSS’03, Newport Beach, CA - USA.
Marcondes, H. and Fröhlich, A. A. M. (2008). “On hybrid hw/sw components for embedded system design.” In Proceedings of the 17th IFAC World Congress, 2008, volume 17, Seoul, South Korea. IFAC.
Mooney, V. and Micheli, G. D. (2000). “Hardware/software codesign of run-time schedulers for real-time systems.” In Proceedings of Design Automation of Embedded Systems, pages 89–144.
P. Kuacharoen, M. S. and Mooney, V. (2003). “A configurable hardware scheduler for real-time systems.” In Proceedings of International Conference on Engineering of Reconfigurable Systems and Algorithms - ERSA’03.
Polpeta, F. V. and Fröhlich, A. A. (2004). “Hardware mediators: a portability artifact for component-based systems.” In Proceedings of International Conference on Embedded and Ubiquitous Computing, volume 3207, pages 271–280.
Polpeta, F. V. and Fröhlich, A. A. (2005). “On the automatic generation of soc-based embedded systems.” In Proceedings of the 10th IEEE International Conference on Emerging Technologies and Factory Automation.
Shalan, M. and Mooney, V. (2000). “A dynamic memory management unit for embedded real-time system-on-a-chip.” In Proceedings of International Conference on Compilers, Architecture and Synthesis for Embedded Systems, pages 180–186.
Shark (2008). S.ha.r.k.: Soft hard real-time kernel. World Wide Web.
Wiedenhoft, G. R. and Fröhlich, A. A. (2008). “Gerência de energia no epos utilizando técnicas da computação imprecisa.” In Proceedings of the Fifth Brazilian Workshop on Operating Systems, pages 34–45.
Publicado
20/07/2009
Como Citar
MARCONDES, Hugo; CANCIAN, Rafael; STEMMER, Marcelo; FRÖHLICH, Antônio Augusto.
Modelagem e Implementação de Escalonadores de Tempo Real para Sistemas Embarcados. In: WORKSHOP DE SISTEMAS OPERACIONAIS (WSO), 6. , 2009, Bento Gonçalves/RS.
Anais [...].
Porto Alegre: Sociedade Brasileira de Computação,
2009
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p. 2405-2416.
