1 /* 2 * Byte ordering utilities. 3 * 4 * Copyright (C) 2023 Paul Boddie <paul@boddie.org.uk> 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License as 8 * published by the Free Software Foundation; either version 2 of 9 * the License, or (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, 19 * Boston, MA 02110-1301, USA 20 */ 21 22 #include "byteorder.h" 23 24 25 26 uint32_t get_stored_value(const uint8_t data[], uint8_t bytes, bool big_endian) 27 { 28 uint32_t value = 0; 29 30 if (big_endian) 31 { 32 for (uint8_t byte = 0; byte < bytes; byte++) 33 value = (value << 8) | data[byte]; 34 } 35 else 36 { 37 for (uint8_t byte = bytes; byte; byte--) 38 value = (value << 8) | data[byte - 1]; 39 } 40 41 return value; 42 } 43 44 void set_stored_value(uint32_t value, uint8_t data[], uint8_t bytes, bool big_endian) 45 { 46 if (big_endian) 47 { 48 for (uint8_t byte = bytes; byte; byte--) 49 { 50 data[byte - 1] = value & 0xff; 51 value >>= 8; 52 } 53 } 54 else 55 { 56 for (uint8_t byte = 0; byte < bytes; byte++) 57 { 58 data[byte] = value & 0xff; 59 value >>= 8; 60 } 61 } 62 }