OPERATING SYSTEMS 1 龚玲 lgong@sjtu.edu.cn
OPERATING SYSTEMS 龚玲 lgong@sjtu.edu.cn 1
OPERATING SYSTEM Silberschatz,Galvin and Gagne c2007
Silberschatz, Galvin and Gagne ©2007 OPERATING SYSTEM
OBJECTIVES o To provide coverage of basic computer system organization o To provide a grand tour of the major operating systems components o http://developer.android.com/sdk/index.html
OBJECTIVES To provide coverage of basic computer system organization To provide a grand tour of the major operating systems components http://developer.android.com/sdk/index.html
COMPUTER SYSTEM ORGANIZATION o Computer-system operation 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 mouse keyboard printer monitor disks on-line CPU disk controller USB controller graphics adapter memory
COMPUTER SYSTEM ORGANIZATION Computer-system operation 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 粗略的了解
OS TOOL:VIRTUAL MACHINE ABSTRACTION Application Virtual Machine Interface Operating System Physical Machine Interface Hardware o Software Engineering Problem: ·Turn hardware./software quirks→ what programmers want/need Optimize for convenience,utilization,security,reliability, etc... o For Any OS area (e.g.file systems,virtual memory, networking,scheduling): o What's the hardware interface?(physical reality) What's the application interface?(nicer abstraction)
OS TOOL: VIRTUAL MACHINE ABSTRACTION Software Engineering Problem: Turn hardware/software quirks what programmers want/need Optimize for convenience, utilization, security, reliability, etc… For Any OS area (e.g. file systems, virtual memory, networking, scheduling): What’s the hardware interface? (physical reality) What’s the application interface? (nicer abstraction) Application Operating System Hardware Physical Machine Interface Virtual Machine Interface