The Embedded Systems track of the X Brazilian Symposium on Computing Systems Engineering (SBESC), an event held online due to the COVID-19 pandemic, received a considerable number of high-quality papers. Considering the ranking produced by the Program Committee, we invited the top papers to submit extended versions, and three articles were selected for inclusion in this special issue.

The first article is entitled “Scheduling and Energy Savings for Small Scale Embedded FreeRTOS-based Real-Time Systems” by Gessé Oliveira and George Lima. The authors presented a study about the effectiveness of system scheduling and energy savings in real-time systems operating in low-computing resources. They evaluated classical scheduling algorithms and implemented and compared them on an ARM-M4 architecture. The presented results serve as a guide for the implementation of scheduling algorithms that can be effectively used for energy saving purposes.

The second article is entitled “Supporting Single and Multi-Core Resource Access Protocols on Object-Oriented RTOSes” by Lucas Matheus dos Santos, Giovani Gracioli, Tomasz Kloda, and Marco Caccamo. The article presents an object-oriented design of real-time access protocols considering single and multi-core systems. Their approach aims to reduce the run-time overhead while increasing code re-usability. An extensive analysis of memory footprint, run-time overhead, and the impact of the overhead on the schedulability are provided by implementing the proposed design in an RTOS running on a modern multi-core processor.

The third article is entitled “Using Evolutionary Metaheuristics to Solve the Mapping and Routing Problem in Networks on Chip” by Hiago Mayk Gomes de Araújo Rocha, Antonio Carlos Schneider Beck Filho, Márcio Eduardo Kreutz, Sílvia Maria Diniz Monteiro Maia, and Monica Magalhães Pereira. In this article, the authors draw attention to the high dependency of task mapping and routing in Networks on Chip based Multiprocessor System on Chip, which led to the development of a joint version of the mapping and routing problems. A mathematical model that generates mapping and routing solutions based on a specific bandwidth of NoC links is presented. This was done in the form of evolutionary metaheuristic algorithms to find optimized solutions for the problem, which were validated by means of experimental procedures.

We would like to express our gratitude to the Technical Program Committee of SBESC for their hard work on reviewing the papers for the conference, also to the additional reviewers who helped us with the review process for this special issue, as well as the authors themselves for their excellent contributions.

Guest Editors