num               139 kernel/syscall.c   int num;
num               142 kernel/syscall.c   num = p->trapframe->a7;
num               143 kernel/syscall.c   if (num > 0 && num < NELEM(syscalls) && syscalls[num]) {
num               146 kernel/syscall.c     p->trapframe->a0 = syscalls[num]();
num               148 kernel/syscall.c     printk("%d %s: unknown sys call %d\n", p->pid, p->name, num);