Reverse Engineering References

[Skarma]

Reversed from Halo CE 1.08 using OllyDbg, IDA Pro, Hexrays, and msdn.

Creates a CRC table from all 256 possible ASCII characters. The only argument used in this function in Halo CE 1.08 is 0x00652968, where the table is stored. This is called only once when Halo first loads up.

The byte at 0x006B4CA0 is set to 1 after the Crc table is initialized.

//----- (004D3840) --------------------------------------------------------

#define Crc32Poly 0xEDB88320
 
void InitCrc32Table(DWORD Crc32Table[256])
{
for(DWORD i = 0; i < 256; i++)
{
 DWORD Crc32 = i;
 
 for(DWORD j = 8; j > 0; j--)
 {
   if(Crc32 & 1)
     Crc32 = (Crc32 >> 1) ^ Crc32Poly;
   else
     Crc32 >>= 1;
 }
 
 Crc32Table[i] = Crc32;
}
}