Operating Systems Chapter 1: Introduction 1 What is an operating system(定义) 12 History of operating systems(历史) 13 The operating system z00(分类) 14 Computer hardware review(底层硬件) 1 Operating system concepts(概念) n1 System calls(系统调用) 17 Operating system structure(结构) Gao Haichang, Software School, Xidian University
Operating Systems Gao Haichang , Software School, Xidian University 4 Chapter 1: Introduction 1.1 What is an operating system (定义) 1.2 History of operating systems (历史) 1.3 The operating system zoo (分类） 1.4 Computer hardware review（底层硬件） 1.5 Operating system concepts（ 概念） 1.6 System calls（系统调用） 1.7 Operating system structure （结构）
Operating Systems 1.1 Definition Banking Airline system reservationbrowser Application programs Command Compilers Editors interpreter Syste programs Operating system Machine language Microarchitecture Hardware Physical devices G A computer system consists of 口 Hardware A system programs H application programs Gao Haichang, Software School, Xidian University
Operating Systems Gao Haichang , Software School, Xidian University 5 1.1 Definition A computer system consists of Hardware system programs application programs
Operating Systems Abstract view of System Components user user user user n compiler assembler text editor database system system and application programs lting system computer hardware Gao Haichang, Software School, Xidian University
Operating Systems Gao Haichang , Software School, Xidian University 6 Abstract View of System Components
Operating Systems Layers of Computer System End User Application Programs OperatIn Utiliti Operating System Computer Hardware Layers and views of a Computer system Gao Haichang, Software School, Xidian University
Operating Systems Gao Haichang , Software School, Xidian University 7 Layers of Computer System Layers and Views of a Computer System
What is an Operating System p opend ing Systems g It is an extended machine top-down view H Hides the messy details which must be performed H Presents user with a virtual machine. easier to use g It is a resource manager bottom-up view m Each program gets time with the resource e.g. Multiple programs run on one CPU H Each program gets space on the resource e.g. main memory is divided up among several running programs Gao Haichang, Software School, Xidian University
Operating Systems Gao Haichang , Software School, Xidian University 8 What is an Operating System? It is an extended machine top-down view Hides the messy details which must be performed. Presents user with a virtual machine, easier to use. It is a resource manager bottom-up view Each program gets time with the resource e.g. Multiple programs run on one CPU. Each program gets space on the resource e.g. Main memory is divided up among several running programs