Chapter 2

Question 1

System Calls?

Answer 1

Provide an interface to the services provided by the OS

Question 2

Most common APIs?

Answer 2

Win32 API for Windows
POSIX API for POSIX based systems, UNIX, LINUX, MAC
Java API for the JVM

Question 3

Types of System Calls?

Answer 3

Process Control
File Management
Device Management
Information Maintenance
Communications
Protection

Question 4

Various ways to structure OS?

Answer 4

Simple Structure - MS-DOS
More Complex - UNIX
Layered - an abstraction
Microkernel - MACH
Hybrid - iOS, Android

Question 5

What is MS-DOS?

Answer 5

Written to provide the most functionality in the least space

Not divided into modules

Question 6

MS-DOS Structure?

Answer 6

Application Program
Resident System Program
MS-DOS device drivers
ROM BIOS device drivers

Question 7

What is Non-Simple Structure – UNIX?

Answer 7

Limited by hardware functionality.
Consists of two parts
System Programs
The Kernel

Question 8

What is Layered Approach?

Answer 8

The OS is divided into number of layers. Bottom is Hardware, outside is User Interface

Question 9

What is Microkernel System Structure?

Answer 9

Moves as much from the kernel into user space

Question 10

What is a Module?

Answer 10

Loaded kernel modules

• Uses OO approach
• Each core component is separate
• Each talks to the others over known interfaces
• Each is loadable as needed within the kernel