1/*-
2 * Copyright (c) 2013 The NetBSD Foundation, Inc.
3 * All rights reserved.
4 *
5 * This code is derived from software contributed to The NetBSD Foundation
6 * by Matt Thomas of 3am Software Foundry.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
18 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
19 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
20 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
21 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29#include <machine/asm.h>
30
31RCSID("$NetBSD: strcpy_thumb.S,v 1.3 2017/01/14 03:00:13 christos Exp $")
32
33#ifdef _LIBC
34#ifdef STRLCPY
35WEAK_ALIAS(strlcpy, _strlcpy)
36#define strlcpy _strlcpy
37#endif
38#ifdef STRNCPY
39WEAK_ALIAS(strncpy, _strncpy)
40#define strncpy _strncpy
41#endif
42#ifdef STRCPY
43WEAK_ALIAS(strcpy, _strcpy)
44#define strcpy _strcpy
45#endif
46#endif
47
48/*
49 * These are "naive" versions of the str*cpy routines designed to be simple
50 * and small.
51 */
52
53#if defined(STRLCPY)
54/* LINTSTUB: size_t strlcpy(char *, const char *, size_t) */
55ENTRY(strlcpy)
56          adds      r3, r1, #1                    /* save src pointer (+ NUL) */
57          subs      r2, r2, #1                    /* make sure there's room for a NUL */
58          blt       3f                            /*   no room, do the strlen */
59          adds      r2, r2, r0                    /* get end of dst */
60          subs      r0, r0, r1                    /* bias against r1 so one incr */
611:        cmp       r0, r2                        /* room for another char? */
62          beq       2f                            /*   no, write NUL and do the strlen */
63          ldrb      r3, [r1]            /* read a byte */
64          strb      r3, [r0, r1]                  /* write a byte */
65          adds      r1, r1, #1                    /* advance to next byte */
66          cmp       r3, #0                        /* was it a NUL? */
67          bne       1b                            /*   no, do next byte */
68          b         4f                            /*   yes, end of string, so return */
692:        movs      r3, #0                        /* NUL */
70          strb      r3, [r0]            /* write to end of string */
713:        ldrb      r3, [r1]            /* read a byte */
72          adds      r1, r1, #1                    /* advance to next byte */
73          cmp       r3, #0                        /* was it a NUL? */
74          bne       3b                            /*   no, get next byte */
754:        subs      r0, r1, r3                    /* return length of src string */
76          RET
77END(strlcpy)
78#elif defined(STRNCPY)
79/* LINTSTUB: char * strncpy(char *, const char *, size_t) */
80ENTRY(strncpy)
81          mov       ip, r0                        /* we want to preserve r0 */
82          adds      r2, r2, r0                    /* get end of dst buffer */
83          subs      r1, r1, r0                    /* allows to only increment once */
841:        cmp       r0, r2                        /* are at the end of dst already? */
85          beq       3f                            /*   yes, just return. */
86          ldrb      r3, [r1, r0]                  /* read a byte */
87          strb      r3, [r0]            /* write a byte */
88          adds      r0, r0, #1                    /* advance a byte */
89          cmp       r3, #0                        /* was it a NUL? */
90          bne       1b                            /*   no, try next byte */
912:        cmp       r0, r2                        /* are at the end of dst already? */
92          beq       3f                            /*   yes, exit loop
93          strb      r3, [r0]            /* write a NUL */
94          adds      r0, r0, #1                    /* advance a bytes */
95          b         2b                            /* until dst is filled */
963:        mov       r0, ip                        /* return dst pointer */
97          RET
98END(strncpy)
99#else
100/* LINTSTUB: char * strcpy(char *, const char *) */
101ENTRY(strcpy)
102          subs      r2, r0, r1                    /* we want to preserve r0 */
1031:        ldrb      r3, [r1]            /* read a byte */
104          strb      r3, [r2, r1]                  /* write a byte */
105          adds      r1, r1, #1                    /* advance to next byte */
106          cmp       r3, #0                        /* was it a NUL? */
107          bne       1b                            /*   no, try next byte */
108          RET                                     /* return dst pointer */
109END(strcpy)
110#endif
111