1 /* 2 * Copyright (C) 2018 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 #ifndef NOS_TRANSPORT_CRC16_H 17 #define NOS_TRANSPORT_CRC16_H 18 19 #include <stdint.h> 20 21 #ifdef __cplusplus 22 extern "C" { 23 #endif 24 25 /** 26 * Calculate the CRC-16 of the data. 27 * 28 * This uses the CRC-16-IBM variant: 0x8005 (x^16 + x^15 + x^2 + 1) 29 */ 30 uint16_t crc16(const void *buf, uint32_t len); 31 32 /** 33 * Calculates the CRC-16 of the data to extend the given crc. 34 * 35 * CRC is a linear function so crc16( x | y ) == crc16(x, crc16(y)). 36 * 37 * This uses the CRC-16-IBM variant: 0x8005 (x^16 + x^15 + x^2 + 1) 38 */ 39 uint16_t crc16_update(const void *buf, uint32_t len, uint16_t crc); 40 41 #ifdef __cplusplus 42 } 43 #endif 44 45 #endif /* NOS_TRANSPORT_CRC16_H */ 46