Subversion Repositories freemyipod

//
//
//    Copyright 2011 TheSeven
//
//
//    This file is part of emCORE.
//
//    emCORE 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.
//
//    emCORE 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 emCORE.  If not, see <http://www.gnu.org/licenses/>.
//
//


#include "global.h"
#include "crc32.h"

static const unsigned int crc32tab[16] =
{
   0x00000000, 0x1db71064, 0x3b6e20c8, 0x26d930ac, 0x76dc4190, 0x6b6b51f4, 0x4db26158, 0x5005713c,
   0xedb88320, 0xf00f9344, 0xd6d6a3e8, 0xcb61b38c, 0x9b64c2b0, 0x86d3d2d4, 0xa00ae278, 0xbdbdf21c
};

uint32_t crc32(const void* data, size_t length)
{
   const uint8_t* buf = (const uint8_t *)data;
   unsigned int crc = 0xffffffff;

   while (length--)
   {
      crc ^= *buf++;
      crc = crc32tab[crc & 0xf] ^ (crc >> 4);
      crc = crc32tab[crc & 0xf] ^ (crc >> 4);
   }

   return crc ^ 0xffffffff;
}