xref: /minix3/common/lib/libc/arch/m68k/string/strncpy.S (revision b6cbf7203b080219de306404f8022a65b7884f33)
1*b6cbf720SGianluca Guida/*	$NetBSD: strncpy.S,v 1.1 2005/12/20 19:28:49 christos Exp $	*/
2*b6cbf720SGianluca Guida
3*b6cbf720SGianluca Guida/*-
4*b6cbf720SGianluca Guida * Copyright (c) 1990 The Regents of the University of California.
5*b6cbf720SGianluca Guida * All rights reserved.
6*b6cbf720SGianluca Guida *
7*b6cbf720SGianluca Guida * This code is derived from software contributed to Berkeley by
8*b6cbf720SGianluca Guida * the Systems Programming Group of the University of Utah Computer
9*b6cbf720SGianluca Guida * Science Department.
10*b6cbf720SGianluca Guida *
11*b6cbf720SGianluca Guida * Redistribution and use in source and binary forms, with or without
12*b6cbf720SGianluca Guida * modification, are permitted provided that the following conditions
13*b6cbf720SGianluca Guida * are met:
14*b6cbf720SGianluca Guida * 1. Redistributions of source code must retain the above copyright
15*b6cbf720SGianluca Guida *    notice, this list of conditions and the following disclaimer.
16*b6cbf720SGianluca Guida * 2. Redistributions in binary form must reproduce the above copyright
17*b6cbf720SGianluca Guida *    notice, this list of conditions and the following disclaimer in the
18*b6cbf720SGianluca Guida *    documentation and/or other materials provided with the distribution.
19*b6cbf720SGianluca Guida * 3. Neither the name of the University nor the names of its contributors
20*b6cbf720SGianluca Guida *    may be used to endorse or promote products derived from this software
21*b6cbf720SGianluca Guida *    without specific prior written permission.
22*b6cbf720SGianluca Guida *
23*b6cbf720SGianluca Guida * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24*b6cbf720SGianluca Guida * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25*b6cbf720SGianluca Guida * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26*b6cbf720SGianluca Guida * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27*b6cbf720SGianluca Guida * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28*b6cbf720SGianluca Guida * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29*b6cbf720SGianluca Guida * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30*b6cbf720SGianluca Guida * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31*b6cbf720SGianluca Guida * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32*b6cbf720SGianluca Guida * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33*b6cbf720SGianluca Guida * SUCH DAMAGE.
34*b6cbf720SGianluca Guida */
35*b6cbf720SGianluca Guida
36*b6cbf720SGianluca Guida#include <machine/asm.h>
37*b6cbf720SGianluca Guida
38*b6cbf720SGianluca Guida#if defined(LIBC_SCCS) && !defined(lint)
39*b6cbf720SGianluca Guida#if 0
40*b6cbf720SGianluca Guida	RCSID("from: @(#)strncpy.s	5.1 (Berkeley) 5/12/90")
41*b6cbf720SGianluca Guida#else
42*b6cbf720SGianluca Guida	RCSID("$NetBSD: strncpy.S,v 1.1 2005/12/20 19:28:49 christos Exp $")
43*b6cbf720SGianluca Guida#endif
44*b6cbf720SGianluca Guida#endif /* LIBC_SCCS and not lint */
45*b6cbf720SGianluca Guida
46*b6cbf720SGianluca GuidaENTRY(strncpy)
47*b6cbf720SGianluca Guida	movl	%sp@(4),%d0		| return value is toaddr
48*b6cbf720SGianluca Guida	movl	%sp@(12),%d1		| count
49*b6cbf720SGianluca Guida	jeq	Lscdone			| nothing to do
50*b6cbf720SGianluca Guida	movl	%sp@(8),%a0		| a0 = fromaddr
51*b6cbf720SGianluca Guida	movl	%d0,%a1			| a1 = toaddr
52*b6cbf720SGianluca Guida	subql	#1,%d1
53*b6cbf720SGianluca GuidaLscloop:
54*b6cbf720SGianluca Guida	movb	%a0@+,%a1@+		| copy a byte
55*b6cbf720SGianluca Guida	dbeq	%d1,Lscloop		| loop through low word of d1
56*b6cbf720SGianluca Guida	jeq	Lscpadding		| copied null, padding if necessary
57*b6cbf720SGianluca Guida	clrw	%d1			| clear low word of d1
58*b6cbf720SGianluca Guida	subql	#1,%d1			| adjust count for long copies
59*b6cbf720SGianluca Guida	jcc	Lscloop			| more room, keep going
60*b6cbf720SGianluca GuidaLscdone:
61*b6cbf720SGianluca Guida#ifdef __SVR4_ABI__
62*b6cbf720SGianluca Guida	moveal	%d0,%a0
63*b6cbf720SGianluca Guida#endif
64*b6cbf720SGianluca Guida	rts
65*b6cbf720SGianluca Guida
66*b6cbf720SGianluca GuidaLscploop:
67*b6cbf720SGianluca Guida	clrb	%a1@+			| clear a byte
68*b6cbf720SGianluca Guida	dbra	%d1,Lscploop		| keep going
69*b6cbf720SGianluca Guida	clrw	%d1
70*b6cbf720SGianluca GuidaLscpadding:
71*b6cbf720SGianluca Guida	subql	#1,%d1
72*b6cbf720SGianluca Guida	jcc	Lscploop
73*b6cbf720SGianluca Guida	jra	Lscdone
74