Operating Systems and File Management Flashcards
Define operating system
A program that controls the execution of application programs and acts as an interface between applications and the computer hardware
What is the difference between user mode and kernel mode?
Kernel mode has elevated instructions over user mode
What is context switching?
The computer switching between user mode and kernel mode
What is a monolithic operating system?
An operating system with a monolithic structure has all services implemented by a large kernel
Pros of a monolithic structure
Communication with the kernel is fast
Cons of a monolithic structure
The large and disorganised code base may be difficult to understand
To add any new service the entire operating system may need to be modified
If any one service fails it may lead to entire system failure
What is a layered operating system?
An operating system with a layered structure has services implemented by a large kernel with a layered organisation
Pros of a layered operating system
Easy to construct and debug
Cons of a layered operating system
Challenging to define the functionality of each layer
Poor performance due to requiring traversal through multiple layers to obtain and operating system service
What is a microkernel operating system?
An operating system with a microkernel structure has services implemented by servers, and a small kernel delivering messages between them
Pros of a microkernel operating system
Extensions are easy
Secure and reliable
Cons of a microkernel operating system
Poor performance due to increased system function overhead
What is a modular operating system?
Services implemented by modules, and a small kernel that loads them on demand
What is bootstrapping?
- The stage on boot loader is run from BIOS ROM
- The stage two boot loader is loaded from disk and run
- The operating system is loaded from disk and run
