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