2007-06-04 13:48:21 +00:00
|
|
|
/***************************************************************************
|
|
|
|
|
* __________ __ ___.
|
|
|
|
|
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
|
|
|
|
|
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
|
|
|
|
|
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
|
|
|
|
|
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
|
|
|
|
|
* \/ \/ \/ \/ \/
|
|
|
|
|
* $Id: crc32.c 10464 2006-08-05 20:19:10Z miipekk $
|
|
|
|
|
*
|
|
|
|
|
* Copyright (C) 2007 Barry Wardell
|
|
|
|
|
*
|
|
|
|
|
* All files in this archive are subject to the GNU General Public License.
|
|
|
|
|
* See the file COPYING in the source tree root for full license agreement.
|
|
|
|
|
*
|
|
|
|
|
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
|
|
|
|
|
* KIND, either express or implied.
|
|
|
|
|
*
|
|
|
|
|
****************************************************************************/
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* We can't use the CRC32 implementation in the firmware library as it uses a
|
|
|
|
|
* different polynomial. The polynomial needed is 0xEDB88320L
|
|
|
|
|
*
|
|
|
|
|
* CRC32 implementation taken from:
|
|
|
|
|
*
|
|
|
|
|
* efone - Distributed internet phone system.
|
|
|
|
|
*
|
|
|
|
|
* (c) 1999,2000 Krzysztof Dabrowski
|
|
|
|
|
* (c) 1999,2000 ElysiuM deeZine
|
|
|
|
|
*
|
|
|
|
|
* 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; either version
|
|
|
|
|
* 2 of the License, or (at your option) any later version.
|
|
|
|
|
*
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/* based on implementation by Finn Yannick Jacobs */
|
|
|
|
|
|
2008-05-03 08:35:14 +00:00
|
|
|
#include "crc32-mi4.h"
|
2007-06-04 13:48:21 +00:00
|
|
|
|
|
|
|
|
/* crc_tab[] -- this crcTable is being build by chksum_crc32GenTab().
|
|
|
|
|
* so make sure, you call it before using the other
|
|
|
|
|
* functions!
|
|
|
|
|
*/
|
|
|
|
|
static unsigned int crc_tab[256];
|
|
|
|
|
|
|
|
|
|
/* chksum_crc() -- to a given block, this one calculates the
|
|
|
|
|
* crc32-checksum until the length is
|
|
|
|
|
* reached. the crc32-checksum will be
|
|
|
|
|
* the result.
|
|
|
|
|
*/
|
|
|
|
|
unsigned int chksum_crc32 (unsigned char *block, unsigned int length)
|
|
|
|
|
{
|
|
|
|
|
register unsigned long crc;
|
|
|
|
|
unsigned long i;
|
|
|
|
|
|
|
|
|
|
crc = 0;
|
|
|
|
|
for (i = 0; i < length; i++)
|
|
|
|
|
{
|
|
|
|
|
crc = ((crc >> 8) & 0x00FFFFFF) ^ crc_tab[(crc ^ *block++) & 0xFF];
|
|
|
|
|
}
|
|
|
|
|
return (crc);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
/* chksum_crc32gentab() -- to a global crc_tab[256], this one will
|
|
|
|
|
* calculate the crcTable for crc32-checksums.
|
|
|
|
|
* it is generated to the polynom [..]
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
void chksum_crc32gentab (void)
|
|
|
|
|
{
|
|
|
|
|
unsigned long crc, poly;
|
|
|
|
|
int i, j;
|
|
|
|
|
|
|
|
|
|
poly = 0xEDB88320L;
|
|
|
|
|
for (i = 0; i < 256; i++)
|
|
|
|
|
{
|
|
|
|
|
crc = i;
|
|
|
|
|
for (j = 8; j > 0; j--)
|
|
|
|
|
{
|
|
|
|
|
if (crc & 1)
|
|
|
|
|
{
|
|
|
|
|
crc = (crc >> 1) ^ poly;
|
|
|
|
|
}
|
|
|
|
|
else
|
|
|
|
|
{
|
|
|
|
|
crc >>= 1;
|
|
|
|
|
}
|
|
|
|
|
}
|
|
|
|
|
crc_tab[i] = crc;
|
|
|
|
|
}
|
|
|
|
|
}
|
