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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2019 HardenedLinux
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <crc_byte.h>
uint8_t crc7_byte(uint8_t prev_crc, uint8_t data)
{
const uint8_t g = 0x89;
prev_crc ^= data;
for (int i = 0; i < 8; i++) {
if (prev_crc & 0x80)
prev_crc ^= g;
prev_crc <<= 1;
}
return prev_crc;
}
uint16_t crc16_byte(uint16_t prev_crc, uint8_t data)
{
prev_crc = (uint8_t)(prev_crc >> 8)|(prev_crc << 8);
prev_crc ^= data;
prev_crc ^= (uint8_t)(prev_crc & 0xff) >> 4;
prev_crc ^= (prev_crc << 8) << 4;
prev_crc ^= ((prev_crc & 0xff) << 4) << 1;
return prev_crc;
}
uint32_t crc32_byte(uint32_t prev_crc, uint8_t data)
{
prev_crc ^= (uint32_t)data << 24;
for (int i = 0; i < 8; i++) {
if ((prev_crc & 0x80000000UL) != 0)
prev_crc = ((prev_crc << 1) ^ 0x04C11DB7UL);
else
prev_crc <<= 1;
}
return prev_crc;
}
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