1/*        $NetBSD: strncpy.S,v 1.5 2013/09/07 19:06:29 chs Exp $      */
2
3/*-
4 * Copyright (c) 1990 The Regents of the University of California.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * the Systems Programming Group of the University of Utah Computer
9 * Science Department.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 * 3. Neither the name of the University nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <machine/asm.h>
37
38#if defined(LIBC_SCCS) && !defined(lint)
39#if 0
40          RCSID("from: @(#)strncpy.s    5.1 (Berkeley) 5/12/90")
41#else
42          RCSID("$NetBSD: strncpy.S,v 1.5 2013/09/07 19:06:29 chs Exp $")
43#endif
44#endif /* LIBC_SCCS and not lint */
45
46ENTRY(strncpy)
47          movl      4(%sp),%d0                    | return value is toaddr
48          movl      12(%sp),%d1                   | count
49          jeq       .Lscdone            | nothing to do
50          movl      8(%sp),%a0                    | a0 = fromaddr
51          movl      %d0,%a1                       | a1 = toaddr
52          subql     #1,%d1
53.Lscloop:
54          movb      (%a0)+,(%a1)+                 | copy a byte
55#ifndef __mcoldfire__
56          dbeq      %d1,.Lscloop                  | loop through low word of d1
57#endif
58          jeq       .Lscpadding                   | copied null, padding if necessary
59#ifndef __mcoldfire__
60          clrw      %d1                           | clear low word of d1
61#endif
62          subql     #1,%d1                        | adjust count for long copies
63          jcc       .Lscloop            | more room, keep going
64.Lscdone:
65#ifdef __SVR4_ABI__
66          moveal    %d0,%a0
67#endif
68          rts
69
70.Lscploop:
71          clrb      (%a1)+                        | clear a byte
72#ifndef __mcoldfire__
73          dbra      %d1,.Lscploop                 | keep going
74          clrw      %d1
75#endif
76.Lscpadding:
77          subql     #1,%d1
78          jcc       .Lscploop
79          jra       .Lscdone
80END(strncpy)
81