关键词: 嵌入式操作系统, 时间/事件触发, 任务调度, 汽车电子类开发系统和对应接口标准/汽车分布式执行标准（OSEK/VDX）, &mu, C/OS-II

Abstract: A mixed kernel architecture of embedded operating system which can support time triggered and event triggered tasks at the same time is designed. The mixed architecture is based on the architecture of μC/OS-II operating system and its interfaces are consistent with OSEK/VDX specification so it is portable. A static, periodic, preemptive scheduling policy for mixed tasks is proposed in the architecture. The scheduling policy supports task switching both at interrupt level and task level and the EDF（Earliest Deadline First） algorithm is used for tasks retrieving. Compared to OSEKtime OS which support task switching only at interrupt level and FIFO（First In First Out） algorithm for tasks retrieving, the proposed policy can improve resource utilization and ensure real-time tasks execution as far as possible. The results of experiment and analysis show that the mixed kernel architecture of embedded operating system is convenient for porting and the scheduling policy proposed for mixed tasks is feasible and effective.

Key words: embedded operating systems, time triggered/event triggered, tasks scheduling, Open System and the Corresponding Interfaces for Automotive Electronics/Vehicle Distributed Executive（OSEK/VDX） standard, μC/OS-II