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Add a CRC module to mbedtls and baremetal config

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Add a new CRC module along with some tests for it.
The table and the CRC function body is generated using pycrc v0.9.2. 
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
This commit is contained in:
Andrzej Kurek 2020-08-07 11:34:21 -04:00
parent 0305753d7a
commit 9df2b416b9
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GPG key ID: 89A90840DC388527
12 changed files with 201 additions and 1 deletions
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library/crc.c Normal file
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/*
* CRC-16/ARC implementation, generated using pycrc v0.9.2, https://pycrc.org,
* with further FI countermeasures added manually.
*
* Used options: --model=crc-16 --algorithm=tbl --generate=c --std=C89 --table-idx-width 4
*
* Copyright (C) 2006-2020, ARM Limited, All Rights Reserved
* SPDX-License-Identifier: Apache-2.0
*
* Licensed 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.
*
* This file is part of mbed TLS (https://tls.mbed.org)
*/
#if !defined(MBEDTLS_CONFIG_FILE)
#include "mbedtls/config.h"
#else
#include MBEDTLS_CONFIG_FILE
#endif
#if defined(MBEDTLS_CRC_C)
#include "mbedtls/crc.h"
static const uint32_t crc_table[16] = {
0x0000, 0xcc01, 0xd801, 0x1400, 0xf001, 0x3c00, 0x2800, 0xe401,
0xa001, 0x6c00, 0x7800, 0xb401, 0x5000, 0x9c01, 0x8801, 0x4400
};
uint16_t mbedtls_crc_update( uint16_t crc, const void *data, size_t data_len )
{
const unsigned char *d = (const unsigned char *)data;
unsigned int tbl_idx;
while ( data_len -- ) {
tbl_idx = crc ^ *d;
crc = crc_table[tbl_idx & 0x0f] ^ ( crc >> 4 );
tbl_idx = crc ^ ( *d >> 4 );
crc = crc_table[tbl_idx & 0x0f] ^ ( crc >> 4 );
d ++;
}
return crc;
}
#endif /* MBEDTLS_CRC_C */