2.9BSD - /usr/src/lib/c/sys/getppid.s

   1: / pid	= getppid();
   2: 
   3: .globl _getppid
   4: 
   5: _getppid:
   6:         mov     r5,-(sp)
   7:         mov     sp,r5
   8:         sys     getpid
   9:         mov     r1,r0
  10:         mov     (sp)+,r5
  11:         rts     pc

Defined functions