CS302 Operating System Week1 Note

What is an operating system?

It is not an "operation" system
- It is operating system
Abstraction of hardware
Software that supports applications
- Managing resources
- resolving conflicts
- handling faults
- preventing attacks, etc.

We will study Operating System
- Concepts & practice
- Overview, Process, Memory, Storage

Special layer of software that provides application software access to hardware resources
- Convenient abstraction of complex hardware device
- Protected access to shared sources
- Security and authentication
- Communication amongst logical entities

Includes a program
- called "kernel", which manages all the physical devices(e.g., CPU, RAM, and hard disk)
- exposes some functions as system calls for others to configure the kernel or building things (e.g., C library) on top
Includes some more programs
- called "drivers", which handles the interaction between the kernel and the external devices(e.g., keyboard)
- called a "shell", which renders a siple command-line user interface with a full set of commands
Includes some "optional" programs
- GUI, Browser, Paintbrush paint

Provide abstractions to apps
- File systems(not a real things)
- Processes, threads
- Virtual memory
Manage resources:
- Memory, CPU, Storage,
- ...
Achieves the above by implementing specific algorithms and techniques
- Scheduling
- Concurrency