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lib/crc: Add CRC32 support

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It only adds CRC32 IEEE support at the moment.

Signed-off-by: Olivier Martin <olivier.martin@proglove.de>
This commit is contained in:
Olivier Martin 2018-04-24 13:56:45 +02:00 • committed by Anas Nashif
commit e7ae7334db
4 changed files with 96 additions and 1 deletions
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56
include/crc32.h Normal file
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@ -0,0 +1,56 @@
/*
* Copyright (c) 2018 Workaround GmbH.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
*
* @brief CRC 32 computation function
*/
#ifndef __CRC32_H
#define __CRC32_H
#include <zephyr/types.h>
#include <stdbool.h>
#include <stddef.h>
/**
* @defgroup checksum Checksum
*/
/**
* @defgroup crc32 CRC 32
* @ingroup checksum
* @{
*/
/**
* @brief Generate IEEE conform CRC32 checksum.
*
* @param *data Pointer to data on which the CRC should be calculated.
* @param len Data length.
*
* @return CRC32 value.
*
*/
u32_t crc32_ieee(const u8_t *data, size_t len);
/**
* @brief Update an IEEE conforming CRC32 checksum.
*
* @param crc CRC32 checksum that needs to be updated.
* @param *data Pointer to data on which the CRC should be calculated.
* @param len Data length.
*
* @return CRC32 value.
*
*/
u32_t crc32_ieee_update(u32_t crc, const u8_t *data, size_t len);
/**
* @}
*/
#endif

2
lib/crc/CMakeLists.txt
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@ -1 +1 @@
zephyr_sources(crc16_sw.c crc8_sw.c)
zephyr_sources(crc32_sw.c crc16_sw.c crc8_sw.c)

26
lib/crc/crc32_sw.c Normal file
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@ -0,0 +1,26 @@
/*
* Copyright (c) 2018 Workaround GmbH.
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <crc32.h>
u32_t crc32_ieee(const u8_t *data, size_t len)
{
return crc32_ieee_update(0x0, data, len);
}
u32_t crc32_ieee_update(u32_t crc, const u8_t *data, size_t len)
{
crc = ~crc;
for (size_t i = 0; i < len; i++) {
crc = crc ^ data[i];
for (u8_t j = 0; j < 8; j++) {
crc = (crc >> 1) ^ (0xEDB88320 & -(crc & 1));
}
}
return (~crc);
}

13
tests/unit/lib/crc/main.c
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@ -6,9 +6,21 @@
#include <ztest.h>
#include <lib/crc/crc32_sw.c>
#include <lib/crc/crc16_sw.c>
#include <lib/crc/crc8_sw.c>
void test_crc32_ieee(void)
{
u8_t test1[] = { 'A' };
u8_t test2[] = { '1', '2', '3', '4', '5', '6', '7', '8', '9' };
u8_t test3[] = { 'Z', 'e', 'p', 'h', 'y', 'r' };
zassert_equal(crc32_ieee(test1, sizeof(test1)), 0xD3D99E8B, NULL);
zassert_equal(crc32_ieee(test2, sizeof(test2)), 0xCBF43926, NULL);
zassert_equal(crc32_ieee(test3, sizeof(test3)), 0x20089AA4, NULL);
}
void test_crc16(void)
{
u8_t test0[] = { };
@ -100,6 +112,7 @@ void test_crc8_ccitt(void)
void test_main(void)
{
ztest_test_suite(test_crc,
ztest_unit_test(test_crc32_ieee),
ztest_unit_test(test_crc16),
ztest_unit_test(test_crc16_ansi),
ztest_unit_test(test_crc16_ccitt),