Chapter 4

Question 1

What are system calls

Answer 1

Kernel execute piece of codes on certain situations. It is called system calls.

Question 2

What is layered approach in OS

Answer 2

The OS is broken into number of layers. Bottom layer is hardware and top most layer is user interface. Lower layer provide services to its upper layer. Its example is IBM’s OS/2.

Question 3

What is microkernel approach

Answer 3

We minimize the kernel in it. It is easy to port to another hardware. Its example is Windows NT

Question 4

What is virtual machine approach

Answer 4

We use CPU scheduling and virtual memory techniques to emulate an underlying hardware on OS. In this way, we can run VM on Windows and install another OS on virtual machine.

Question 5

What is the root directory in linux/unix

Answer 5

/

Question 6

Which directory holds binary executable files

Answer 6

bin

Question 7

Which directory holds essential boot files

Answer 7

boot

Question 8

What is super user in real time system

Answer 8

Super user is system administrator

Question 9

Does linux/unix has command line interface

Answer 9

Yes