source: mainline/kernel/generic/src/lib/mem.c@ 0b5203b

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since 0b5203b was 174156fd, checked in by Jakub Jermar <jakub@…>, 7 years ago

Disambiguate doxygroup generic*

  • Property mode set to 100644
File size: 3.3 KB
Line 
1/*
2 * Copyright (c) 2001-2004 Jakub Jermar
3 * Copyright (c) 2008 Jiri Svoboda
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * - Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * - Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * - The name of the author may not be used to endorse or promote products
16 * derived from this software without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30/** @addtogroup kernel_generic
31 * @{
32 */
33
34/**
35 * @file
36 * @brief Memory string operations.
37 *
38 * This file provides architecture independent functions to manipulate blocks
39 * of memory. These functions are optimized as much as generic functions of
40 * this type can be.
41 */
42
43#include <mem.h>
44#include <typedefs.h>
45
46/** Fill block of memory.
47 *
48 * Fill cnt bytes at dst address with the value val.
49 *
50 * @param dst Destination address to fill.
51 * @param cnt Number of bytes to fill.
52 * @param val Value to fill.
53 *
54 */
55void memsetb(void *dst, size_t cnt, uint8_t val)
56{
57 memset(dst, val, cnt);
58}
59
60/** Fill block of memory.
61 *
62 * Fill cnt words at dst address with the value val. The filling
63 * is done word-by-word.
64 *
65 * @param dst Destination address to fill.
66 * @param cnt Number of words to fill.
67 * @param val Value to fill.
68 *
69 */
70void memsetw(void *dst, size_t cnt, uint16_t val)
71{
72 size_t i;
73 uint16_t *ptr = (uint16_t *) dst;
74
75 for (i = 0; i < cnt; i++)
76 ptr[i] = val;
77}
78
79/** Move memory block with possible overlapping.
80 *
81 * Copy cnt bytes from src address to dst address. The source
82 * and destination memory areas may overlap.
83 *
84 * @param dst Destination address to copy to.
85 * @param src Source address to copy from.
86 * @param cnt Number of bytes to copy.
87 *
88 * @return Destination address.
89 *
90 */
91void *memmove(void *dst, const void *src, size_t cnt)
92{
93 /* Nothing to do? */
94 if (src == dst)
95 return dst;
96
97 /* Non-overlapping? */
98 if ((dst >= src + cnt) || (src >= dst + cnt))
99 return memcpy(dst, src, cnt);
100
101 uint8_t *dp;
102 const uint8_t *sp;
103
104 /* Which direction? */
105 if (src > dst) {
106 /* Forwards. */
107 dp = dst;
108 sp = src;
109
110 while (cnt-- != 0)
111 *dp++ = *sp++;
112 } else {
113 /* Backwards. */
114 dp = dst + (cnt - 1);
115 sp = src + (cnt - 1);
116
117 while (cnt-- != 0)
118 *dp-- = *sp--;
119 }
120
121 return dst;
122}
123
124/** @}
125 */
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