xref: /aosp_15_r20/external/openthread/examples/platforms/utils/encoding.h (revision cfb92d1480a9e65faed56933e9c12405f45898b4)
1 /*
2  *  Copyright (c) 2020, The OpenThread Authors.
3  *  All rights reserved.
4  *
5  *  Redistribution and use in source and binary forms, with or without
6  *  modification, are permitted provided that the following conditions are met:
7  *  1. Redistributions of source code must retain the above copyright
8  *     notice, this list of conditions and the following disclaimer.
9  *  2. Redistributions in binary form must reproduce the above copyright
10  *     notice, this list of conditions and the following disclaimer in the
11  *     documentation and/or other materials provided with the distribution.
12  *  3. Neither the name of the copyright holder nor the
13  *     names of its contributors may be used to endorse or promote products
14  *     derived from this software without specific prior written permission.
15  *
16  *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17  *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20  *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23  *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24  *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25  *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26  *  POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /**
30  * @file
31  *   This file includes macros for validating runtime conditions.
32  */
33 
34 #ifndef PLATFORM_UTILS_ENCODING_H
35 #define PLATFORM_UTILS_ENCODING_H
36 
37 #include <stdint.h>
38 
39 /**
40  * Converts a 64-bit unsigned integer stored as a little-endian byte
41  * array to uint64_t.
42  *
43  * Allows for the array to be byte-aligned, so that loading the
44  * uint64_t value via this function avoids a processor exception due
45  * to unaligned access.
46  *
47  * @param[in]  aSource  The byte array.
48  *
49  * @returns The 64-bit value as a uint64_t.
50  *
51  */
otEncodingReadUint64Le(const uint8_t * aSource)52 static inline uint64_t otEncodingReadUint64Le(const uint8_t *aSource)
53 {
54     uint64_t value = 0;
55 
56     value |= (uint64_t)aSource[0];
57     value |= ((uint64_t)aSource[1]) << 8;
58     value |= ((uint64_t)aSource[2]) << 16;
59     value |= ((uint64_t)aSource[3]) << 24;
60     value |= ((uint64_t)aSource[4]) << 32;
61     value |= ((uint64_t)aSource[5]) << 40;
62     value |= ((uint64_t)aSource[6]) << 48;
63     value |= ((uint64_t)aSource[7]) << 56;
64 
65     return value;
66 }
67 
68 #endif // PLATFORM_UTILS_ENCODING_H
69