50 lines
1.3 KiB
C
50 lines
1.3 KiB
C
|
/*
|
|||
|
|
*********************************************************************************************************
|
|||
|
|
* ePDK
|
|||
|
|
* the Easy Portable/Player Develop Kits
|
|||
|
|
* Decompression For Boot
|
|||
|
|
*
|
|||
|
|
* (c) Copyright 2009-2010, Sunny China
|
|||
|
|
* All Rights Reserved
|
|||
|
|
*
|
|||
|
|
* File : calc_crc32.c
|
|||
|
|
* By : sunny
|
|||
|
|
* Version : V2.0
|
|||
|
|
* Date : 2009-11-4 10:34:26
|
|||
|
|
*********************************************************************************************************
|
|||
|
|
*/
|
|||
|
|
#include "crc.h"
|
|||
|
|
|
|||
|
|
unsigned int calc_crc32(void * buffer, unsigned int length)
|
|||
|
|
{
|
|||
|
|
unsigned int i, j;
|
|||
|
|
CRC32_DATA_t crc32; //
|
|||
|
|
unsigned int CRC32 = 0xffffffff; //<2F><><EFBFBD>ó<EFBFBD>ʼֵ
|
|||
|
|
|
|||
|
|
crc32.CRC = 0;
|
|||
|
|
|
|||
|
|
for( i = 0; i < 256; ++i)//<2F><>++i<><69><EFBFBD><EFBFBD><EFBFBD><EFBFBD>Ч<EFBFBD><D0A7>
|
|||
|
|
{
|
|||
|
|
crc32.CRC = i;
|
|||
|
|
for( j = 0; j < 8 ; ++j)
|
|||
|
|
{
|
|||
|
|
//<2F><><EFBFBD><EFBFBD>ѭ<EFBFBD><D1AD>ʵ<EFBFBD><CAB5><EFBFBD>Ͼ<EFBFBD><CFBE><EFBFBD><EFBFBD><EFBFBD>"<22><><EFBFBD>㷨"<22><><EFBFBD><EFBFBD>ȡCRC<52><43>У<EFBFBD><D0A3><EFBFBD><EFBFBD>
|
|||
|
|
if(crc32.CRC & 1)
|
|||
|
|
crc32.CRC = (crc32.CRC >> 1) ^ 0xEDB88320;
|
|||
|
|
else //0xEDB88320<32><30><EFBFBD><EFBFBD>CRC-32<33><32><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD><EFBFBD>ʽ<EFBFBD><CABD>ֵ
|
|||
|
|
crc32.CRC >>= 1;
|
|||
|
|
}
|
|||
|
|
crc32.CRC_32_Tbl[i] = crc32.CRC;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
CRC32 = 0xffffffff; //<2F><><EFBFBD>ó<EFBFBD>ʼֵ
|
|||
|
|
for( i = 0; i < length; ++i)
|
|||
|
|
{
|
|||
|
|
CRC32 = crc32.CRC_32_Tbl[(CRC32^((unsigned char*)buffer)[i]) & 0xff] ^ (CRC32>>8);
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
//return CRC32;
|
|||
|
|
return CRC32^0xffffffff;
|
|||
|
|
}
|
|||
|
|
|