关键词: 时间/事件触发, 嵌入式系统, 内核, 安全访问

Abstract: With the increment of the unpredictability of external events and the complexity of real-time task, it is becoming more and more difficult to design an embedded real-time operating system only by traditional event-triggered-based mechanism. In many cases, the system is difficult to guarantee the safety and reliability in real-time processing. Because the designer of μC/OS-Ⅱ did not consider the time-triggered tasks and the security access control mechanism at the beginning of the design, combined with the time-triggered OSEK standard, this paper designs and implements a kernel scheduling mechanism which not only  can correspond to OSEK standard but also support the time-triggered and event-triggered tasks. In addition, it also can achieve an access control for security system by using GFAC and a security attribute mapping table. The experimental results show that the designed scheduling mechanism and access control method not only meet the double triggered characteristics, but also enhance the security access control for kernel, and have a good efficiency.

Key words: time and event triggered, embedded system, kernel； security access