V5/usr/source/s4/execl.s

Find at most related files.
including files from this version of Unix. 
/ C library -- execl

/ execl(file, arg1, arg2, ... , 0);
/

.globl	_execl, cerror

_execl:
	mov	r5,-(sp)
	mov	sp,r5
	mov	4(r5),0f
	mov	r5,r0
	add	$6,r0
	mov	r0,0f+2
	sys	0; 9f
	jmp	cerror
.data
9:
	sys	exec; 0:..; ..