Quiz# 4: System Calls

1. What is the relationship between a trap and an interrupt?

Interrupts have a service routine, traps do not.
An interrupt is a software generated trap.
A trap is a software generated interrupt.

2. System calls are

used by user programs to access the OS kernel code to which they ordinarilydo not have access to.
needed because we want to use the interrupt service routines.
functions or instructions that are executed on behalf of the user programs bythe OS.

3. How is a system call implemented?



4. How does the kernel know the parameters passed to the system call by the calling program?



5. In order to make a system call, the user program must know how the OS refers to that system call and place an appropriate code in some pre-specified register.

True
False