bit20403chapt02 (2).pdf - CHAPTER 02 Computer-System...

Computer-System
Structures
C HAPTER 0 2
1

1. General Computer-System
Architecture
2. Computer System Operation
3. Common Functions of Interrupts
4. I/O Structure
5. Storage Structure
6. Storage Hierarchy
7. Hardware Protection
Contents
2

Chapter objectives:
• To describe the basic organization of
computer systems.
• To provide a grand tour of the major
components of operating systems.
• To give an overview of the many types of
computing environments.
3

Computer-System
Architecture
4

Computer-System
Operation
• I/O devices and the CPU can execute concurrently.
• Each device controller is in charge of a particular
device type.
• Each device controller has a local buffer .
• CPU moves data from/to main memory to/from local
buffers.
• I/O is from the device to local buffer of controller.
• Device controller informs CPU that it has finished its
operation by causing an interrupt.
5

Computer-System
Operation
• What is Buffer??
BIC20803 Operating Systems: Chapter 2 6

Computer startup - Bootstrap
Program / BIOS
7

• Bootstrap Program / BIOS;
–
.
Computer Startup
8

Computer Startup
– Stored in ROM within the computer system
– Performs 2 tasks:
1. scan the components in the system,
initializes all aspects of the computer
system, from CPU register to device
controllers to memory content.
2. scan the list of boot devices (floppy disk, CD
/ DVD drive, one or more hard disk drives)
looking for a boot loader
9

Common Functions of
Interrupts
 What is interrupt?
10

Common Functions of
Interrupts
 Device controller informs CPU that it has
finished its operation by causing an interrupt .
 2 types of interrupts:
1. Hardware → trigger an interrupt at any time
by sending a signal to the CPU , usually by
way of the system bus.
2. Software → trigger an interrupt by executing
system call (kernel call) ( a computer program
requests a service from the kernel of the
operating system it is executed on. )
11

Common Functions of
Interrupts
•