计算机工程与应用
計算機工程與應用
계산궤공정여응용
COMPUTER ENGINEERING AND APPLICATIONS
2015年
15期
6-11
,共6页
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)%μC/OS-II
嵌入式操作繫統%時間/事件觸髮%任務調度%汽車電子類開髮繫統和對應接口標準/汽車分佈式執行標準(OSEK/VDX)%μC/OS-II
감입식조작계통%시간/사건촉발%임무조도%기차전자류개발계통화대응접구표준/기차분포식집행표준(OSEK/VDX)%μC/OS-II
embedded operating systems%time triggered/event triggered%tasks scheduling%Open System and the Corre-sponding Interfaces for Automotive Electronics/Vehicle Distributed Executive(OSEK/VDX)standard%μC/OS-II
针对当前嵌入式系统中时间触发与事件触发混合任务的特点，以μC/OS-II操作系统架构为基础，设计了一种能够同时支持时间触发与事件触发的混合操作系统内核架构。该架构符合OSEK/VDX标准，具有良好的可移植性。针对混合任务调度问题，提出了一种静态周期性可抢占式混合任务调度策略，该策略同时支持中断级与任务级的任务切换，并采用EDF（最早截止时间优先）算法对被抢占的时间触发任务进行恢复，相比OSEKtime OS只能在中断级进行任务切换以及FIFO（先进先出）恢复算法，能够提高系统资源利用率，并最大限度保证任务实时性。实验分析结果表明，所设计的混合操作系统架构移植方便，所提出的混合任务调度策略可行有效，调度过程具有良好的可预测性。
針對噹前嵌入式繫統中時間觸髮與事件觸髮混閤任務的特點，以μC/OS-II操作繫統架構為基礎，設計瞭一種能夠同時支持時間觸髮與事件觸髮的混閤操作繫統內覈架構。該架構符閤OSEK/VDX標準，具有良好的可移植性。針對混閤任務調度問題，提齣瞭一種靜態週期性可搶佔式混閤任務調度策略，該策略同時支持中斷級與任務級的任務切換，併採用EDF（最早截止時間優先）算法對被搶佔的時間觸髮任務進行恢複，相比OSEKtime OS隻能在中斷級進行任務切換以及FIFO（先進先齣）恢複算法，能夠提高繫統資源利用率，併最大限度保證任務實時性。實驗分析結果錶明，所設計的混閤操作繫統架構移植方便，所提齣的混閤任務調度策略可行有效，調度過程具有良好的可預測性。
침대당전감입식계통중시간촉발여사건촉발혼합임무적특점，이μC/OS-II조작계통가구위기출，설계료일충능구동시지지시간촉발여사건촉발적혼합조작계통내핵가구。해가구부합OSEK/VDX표준，구유량호적가이식성。침대혼합임무조도문제，제출료일충정태주기성가창점식혼합임무조도책략，해책략동시지지중단급여임무급적임무절환，병채용EDF（최조절지시간우선）산법대피창점적시간촉발임무진행회복，상비OSEKtime OS지능재중단급진행임무절환이급FIFO（선진선출）회복산법，능구제고계통자원이용솔，병최대한도보증임무실시성。실험분석결과표명，소설계적혼합조작계통가구이식방편，소제출적혼합임무조도책략가행유효，조도과정구유량호적가예측성。
A mixed kernel architecture of embedded operating system which can support time triggered and event trig-gered tasks at the same time is designed. The mixed architecture is based on the architecture ofμC/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 pro-posed policy can improve resource utilization and ensure real-time tasks execution as far as possible. The results of experi-ment 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.
