66 lines
2.0 KiB
C++
66 lines
2.0 KiB
C++
/*
|
|
* This file is a consolidation of functions required for tfe
|
|
* emulation taken from the following files
|
|
*
|
|
* lib.c - Library functions.
|
|
* util.c - Miscellaneous utility functions.
|
|
* crc32.c
|
|
*
|
|
* Written by
|
|
* Andreas Boose <viceteam@t-online.de>
|
|
* Ettore Perazzoli <ettore@comm2000.it>
|
|
* Andreas Matthies <andreas.matthies@gmx.net>
|
|
* Tibor Biczo <crown@mail.matav.hu>
|
|
* Spiro Trikaliotis <Spiro.Trikaliotis@gmx.de>*
|
|
*
|
|
* This file is part of VICE, the Versatile Commodore Emulator.
|
|
* See README for copyright notice.
|
|
*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
|
|
* 02111-1307 USA.
|
|
*
|
|
*/
|
|
|
|
#include "tfesupp.h"
|
|
|
|
#define CRC32_POLY 0xedb88320
|
|
static unsigned long crc32_table[256];
|
|
static int crc32_is_initialized = 0;
|
|
|
|
// crc32 Stuff
|
|
|
|
unsigned long crc32_buf(const char *buffer, unsigned int len)
|
|
{
|
|
int i, j;
|
|
unsigned long crc, c;
|
|
const char *p;
|
|
|
|
if (!crc32_is_initialized) {
|
|
for (i = 0; i < 256; i++) {
|
|
c = (unsigned long) i;
|
|
for (j = 0; j < 8; j++)
|
|
c = c & 1 ? CRC32_POLY ^ (c >> 1) : c >> 1;
|
|
crc32_table[i] = c;
|
|
}
|
|
crc32_is_initialized = 1;
|
|
}
|
|
|
|
crc = 0xffffffff;
|
|
for (p = buffer; len > 0; ++p, --len)
|
|
crc = (crc >> 8) ^ crc32_table[(crc ^ *p) & 0xff];
|
|
|
|
return ~crc;
|
|
}
|