Os

Question 1

What is an os

Answer 1

An intermedia between hardware and software which make a interface to users

Question 2

When boostrap loads

Answer 2

At power up or reboot

Question 3

Where boostrap stored

Answer 3

Rom known as firmware

Question 4

Rom ?

Answer 4

Coded instructions stored permanently in Rom

Question 5

What boostrap do

Answer 5

Initializes all aspects of system
Loads operating system kernel and starts execution

Question 6

How bosstrap prosses works.what are the two stages

Answer 6

Rom holds the boostrap program.when the computer turns on cpu counter is set to the first instruction of boostrap and execute the instructions.when loading done the program counter is set to the first instruction of the os in ram

Question 7

How the boostrap works? graphical?

Answer 7

boostrap runs
Os loads
Os runs

Question 8

Innterput service routine?

Answer 8

Segements of code thatdeyerminea action to be taken for each type of interrupt

Question 9

Interrupt vector means

Answer 9

Contain the adreessof service routines

Question 10

What is done to prevent lost inrerrupt?

Answer 10

Incoming interupta are disabled while another interrupt is being processed.

Question 11

Interrupt types?

Answer 11

Polling
Vectored

Question 12

How do we know that i/o is complete in polling? Interrupt ?

Question 13

How do we know that I/O is complete? (polling)

Answer 13

▪ Device sets a flag when it is busy.
▪ Program tests the flag in a loop waiting for completion of I/O.

Question 14

How do we know that I/O is complete? (interrupts)

Answer 14

▪ On completion of I/O, device forces CPU to jump to a specific instruction address that contains
the interrupt service routine.
▪ After the interrupt has been processed, CPU returns to code it was executing prior to servicing
the interrupt