摘要： 传统操作系统核内驱动的I/O结构无法满足嵌入式操作系统的需要，核外I/O技术的实现难点是如何将外部中断从核内引向核外，分析了基于信号机制的核外I/O的实现方法，并提出了一种由系统核心ISR直接跳转到核外驱动程序ISR的核外硬中断方法及其实现方法。

关键词: 嵌入式, 操作系统, I/O, 核外

Abstract: User-level I/O gets increasingly important for embedded real-time applications. To support user-level I/O for embedded systems, an operating system must provide a mechanism to deliver an external interrupt from an I/O device to a process in a predictable and efficient manner. This paper discusses two schemes to implement user-level I/O, of which one is based on signal mechanism, the other is based on hard deliver of external interrupt.

中图分类号: 

• TP316.2