ETRI Journal
- Volume 29 Issue 3
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- Pages.259-269
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- 2007
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- 1225-6463(pISSN)
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- 2233-7326(eISSN)
UbiFOS: A Small Real-Time Operating System for Embedded Systems
- Ahn, Hee-Joong (Digital Home Research Division, ETRI) ;
- Cho, Moon-Haeng (Department of Computer Engineering, Chungnam National University) ;
- Jung, Myoung-Jo (Department of Computer Engineering, Chungnam National University) ;
- Kim, Yong-Hee (Department of Computer Engineering, Chungnam National University) ;
- Kim, Joo-Man (Department of BioInformation & Electronics, Pusan National University) ;
- Lee, Cheol-Hoon (Department of Computer Engineering, Chungnam National University)
- Received : 2006.10.09
- Published : 2007.06.30
Abstract
The ubiquitous flexible operating system (UbiFOS) is a real-time operating system designed for cost-conscious, low-power, small to medium-sized embedded systems such as cellular phones, MP3 players, and wearable computers. It offers efficient real-time operating system services like multi-task scheduling, memory management, inter-task communication and synchronization, and timers while keeping the kernel size to just a few to tens of kilobytes. For flexibility, UbiFOS uses various task scheduling policies such as cyclic time-slice (round-robin), priority-based preemption with round-robin, priority-based preemptive, and bitmap. When there are less than 64 tasks, bitmap scheduling is the best policy. The scheduling overhead is under 9