operating systems

Question

system call is

a)hardware interrupts

b)software interrupt

c)exception

d)none o these

i feel all a,b,c :(

Answer 1

System calls provide an interface between the process an the operating system. System calls allow user-level processes to request some services from the operating system which process itself is not allowed to do. In handling the trap, the operating system will enter in the kernel mode, where it has access to privileged instructions, and can perform the desired service on the behalf of user-level process .so user for getting their service genrate s/w intrupts in the form of system call thats why system call is s/w intrupts 

Comments

hardware interrupt are also done by system calls correct me if i am wrong

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ya i think u r right .

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i think answer should be a,b ,c

Answer 2

When the C library has loaded the system call index and any arguments, a software interrupt is invoked (interrupt 0x80), which results in execution through the interrupt handler  of the system call function.So it is a software interrupt.

To know more about system call mechanism go through this link.

http://www.ibm.com/developerworks/library/l-system-calls/

Answer 3

Yes It can occur in any of the situation .

Comments

@manojk : Just verify !

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but the answer is b

Answer 4

answer is option B) Software Interrupt

A call to the operating system by a process to perform something which os is privileged to do so is a System call, a process is a software.

Comments

why not a ,c