/* * Copyright (c) 2001-2007 Apple Inc. All Rights Reserved. * * @APPLE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in * compliance with the License. Please obtain a copy of the License at * http://www.opensource.apple.com/apsl/ and read it before using this * file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. * Please see the License for the specific language governing rights and * limitations under the License. * * @APPLE_LICENSE_HEADER_END@ */ /* * BLBlockChecksum.c * bless * * Created by Shantonu Sen <ssen@apple.com> on Wed Feb 28 2002. * Copyright (c) 2002-2007 Apple Inc. All Rights Reserved. * * $Id: BLBlockChecksum.c,v 1.8 2006/02/20 22:49:56 ssen Exp $ * */ #include <sys/types.h> #include "bless_private.h" /* * Taken from MediaKit. Used to checksum secondary loader * presently */ uint32_t BLBlockChecksum(const void *buf,uint32_t length) { uint32_t sum = 0; uint32_t *s = (uint32_t *) buf; uint32_t *t = s + length/4; while (s < t) { // rotate 1 bit left and add bytes sum = ((sum >> 31) | (sum << 1)) + *s++; } return sum; }