Add original unix v6

source/s5/nlist.s

@@ -0,0 +1,98 @@
+/ nlist -- extract values from name list
+/
+
+/	nlist(file, list);
+/
+.globl	_nlist
+
+_nlist:
+	mov	r5,-(sp)
+	mov	sp,r5
+	mov	4(r5),0f
+	mov	6(r5),r1
+	mov	r2,-(sp)
+
+	mov	r1,r0
+1:
+	tst	(r0)
+	beq	1f
+	add	$8.,r0
+	clr	(r0)+
+	clr	(r0)+			/ initialize to undefined
+	br	1b
+1:
+	sys	0; 9f
+.data
+9:
+	sys	open; 0:..; 0
+.text
+	bes	done
+	mov	r0,r2
+	sys	read; buf; 20
+	cmp	r0,$20
+	bne	cdone
+	mov	buf+4,count			/ assume older a.out
+	mov	buf+2,0f
+	cmp	buf,$405
+	beq	1f
+	mov	buf+8.,count			/ now assume newer
+	mov	buf+2,r0			/ txt
+	add	buf+4,r0			/ data
+	cmp	buf+16,$1			/ relocation?
+	beq	4f
+	asl	r0				/ txt+data reloc
+4:
+	add	$20,r0				/ header
+	mov	r0,0f
+	cmp	buf,$411
+	beq	1f
+	cmp	buf,$410
+	beq	1f
+	cmp	buf,$407
+	bne	cdone
+1:
+	mov	r2,r0
+	sys	0; 9f
+.data
+9:
+	sys	seek; 0:..; 0
+.text
+
+1:
+	sub	$12.,count
+	blt	cdone
+	mov	r2,r0
+	sys	read; buf; 12.
+	cmp	r0,$12.
+	bne	cdone
+	mov	r1,r0
+
+2:
+	tst	(r0)
+	beq	1b
+	cmp	(r0),buf
+	bne	1f
+	cmp	2(r0),buf+2
+	bne	1f
+	cmp	4(r0),buf+4
+	bne	1f
+	cmp	6(r0),buf+6
+	bne	1f
+	mov	buf+8.,8.(r0)
+	mov	buf+10.,10.(r0)
+1:
+	add	$12.,r0
+	br	2b
+
+cdone:
+	mov	r2,r0
+	sys	close
+
+done:
+	mov	(sp)+,r2
+	mov	(sp)+,r5
+	rts	pc
+
+.bss
+buf:	.=.+20
+count:	.=.+2