[理学]西安交通大学操作系统原理第一章.ppt

1 Introduction 操作系统引论 What is an operating system? Development and Types of OS The features of OS The functions of OS Computer System Organization One or more CPUs, device controllers connect through common bus providing access to shared memory Concurrent execution of CPUs and devices competing for memory cycles Computer-System Operation I/O devices and the CPU can execute concurrently Each device controller is in charge of a particular device type Each device controller has a local buffer CPU moves data from/to main memory to/from local buffers I/O is from the device to local buffer of controller Device controller informs CPU that it has finished its operation by causing an interrupt Common Functions of Interrupts Interrupt transfers control to the interrupt service routine generally, through the interrupt vector, which contains the addresses of all the service routines Interrupt architecture must save the address of the interrupted instruction A trap is a software-generated interrupt caused either by an error or a user request An operating system is interrupt driven Abstract View of System structure Computer system structure Hardware – provides basic computing resources (CPU, memory, I/O devices).提供基本的运算资源 Operating system – controls and coordinates the use of the hardware among the various application programs for the various users.在各种应用程序和用户之间控制与协调对硬件的使用 Computer system structure(cont.) Applications programs– define the ways in which the system resources are used to solve the computing problems of the users (compilers, database systems, video games, business programs).应用程序-定义解决用户问题的资源使用方式（编译、数据库、视频游戏、事务程序等） Users (people, machines, other computers)用户（人、机、其他计算机）. Resources in computer system Computer Startup 1.1 What is an operating system? Operating System:操作系统? Operating Surgeon:主刀大夫,掌控整个手术过程 Operating Person:操刀手,掌控事情的人 Operating System:掌控局势的一种系统,计算机中的一切均由其掌控 管理计算机中的资源 保证资源的公平使用 防止对计算机资源的非法使用 保证操作系统自身正常运转 1.1 What is an Operating System? A program that a