written 7.3 years ago by | • modified 7.3 years ago |
Mumbai University > Computer Engineering > Sem 5 > Operating System
Marks: 5M
Years: May 2016
written 7.3 years ago by | • modified 7.3 years ago |
Mumbai University > Computer Engineering > Sem 5 > Operating System
Marks: 5M
Years: May 2016
written 7.3 years ago by |
System calls provide an interface to the services made available by an operating system.
We know that there are two main modes in the operation of the system, that is the user mode and kernel mode.
However many a times user-mode programs need to execute some privileged operations in kernel mode. Since processor prevents direct access to kernel-mode functions, we need to use an interface.
Definition: System calls provide an interface to the services made available by an operating system.
System calls expose all kernel functionalities that user-mode programs require.
The main advantage of system calls is security. Due to system calls a user program is not able to enter into the OS or any other users region.
Similarly, I/O devices are free from any misuse by the user.