September 18, 2016
Categorised in: Operating System Design
What is operating system?
- Computer = set of resources
- Processors, memory, I/O & communication devices
- Enable use of resources
- Manage resources
- The low-level software that supports a computer’s basic functions, such as scheduling tasks and controlling peripherals
- Resources not limited to hardware
Operating system components
- Processor scheduler
- Memory manager
- I/O manager
- Inter-process communication manager
- File system manager
Operating system booting
- Booting is a bootstrapping process that starts OS when the user turns on computer system
- Boot sequence is set of operations the computer performs when it is switched on that load an operating system
- During bootstrapping, the kernel is loaded into memory and begins to execute.
- A variety of initialization tasks are performed and then the system is made available to users
- The primitive loader program that can load and execute the boot program is called Bootstrap program, and it is typically stored in ROM.
- On start up, computer automatically reads the bootstrap program.
- The boot program is generally stored on disk with predetermined address, called boot sector.
- The boot program then loads the operating system into memory, this is called bootstrapping.