testmycall.h
Create a header file called testmycall.h. This header file should be included by any program calling our system call.
Add three lines to it
Line 1: This is needed because we need the definition of _syscall1.
#include<linux/unistd.h>
Line 2: This is needed because we need the number of our system call.
#define __NR_mycall 317
Line 3: This is needed for system calls with 1 argument. It is explained in detail below.
_syscall1(long, mycall, int, i)
So, our user header file looks like:
/*---Start of header file------*/
#include<linux/unistd.h>
#define __NR_mycall 317
_syscall1(long, mycall, int, i)
/*---End of header file--------*/