incubator-nuttx/libs/libc/misc/lib_crc8table.c

58 lines
2.0 KiB
C

/****************************************************************************
* libs/libc/misc/lib_crc8table.c
*
* SPDX-License-Identifier: Apache-2.0
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <sys/types.h>
#include <stdint.h>
#include <nuttx/crc8.h>
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: crc8table
*
* Description:
* Return a 8-bit CRC of the contents of the 'src' buffer, length 'len'
* using a CRC with crc table used for calculation.
*
****************************************************************************/
uint8_t crc8table(const uint8_t table[256], const uint8_t *src,
size_t len, uint8_t crc8val)
{
size_t i;
crc8val ^= 0xff;
for (i = 0; i < len; i++)
{
crc8val = table[crc8val ^ src[i]];
}
return crc8val ^ 0xff;
}