bitfield.h   [plain text]


/*
 * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
 *
 * @APPLE_LICENSE_HEADER_START@
 * 
 * Copyright (c) 1999-2003 Apple Computer, Inc.  All Rights Reserved.
 * 
 * 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@
 */
//
// bitfield.h - extract and set bit fields
//
// Written by Eryk Vershen (eryk@apple.com)
//
// Bitfields are not particularly transportable between big and little
// endian machines.  Big endian machines lay out bitfields starting
// from the most significant bit of the (one, two or four byte) number,
// whereas little endian machines lay out bitfields starting from the
// least signifcant bit.
//
// These routines were written to support some bitfields in a disk
// data structure (partition map) whose original definition was on
// a big-endian machine.
//
// They only work on 32-bit values because I didn't need 16-bit support.
// The bits in the long word are numbered from 0 (least significant) to
// 31 (most significant).
//

/*
 * Copyright 1996 by Apple Computer, Inc.
 *              All Rights Reserved 
 *  
 * Permission to use, copy, modify, and distribute this software and 
 * its documentation for any purpose and without fee is hereby granted, 
 * provided that the above copyright notice appears in all copies and 
 * that both the copyright notice and this permission notice appear in 
 * supporting documentation. 
 *  
 * APPLE COMPUTER DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 
 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 
 * FOR A PARTICULAR PURPOSE. 
 *  
 * IN NO EVENT SHALL APPLE COMPUTER BE LIABLE FOR ANY SPECIAL, INDIRECT, OR 
 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, 
 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 
 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 
 */


//
// Defines
//


//
// Types
//


//
// Global Constants
//


//
// Global Variables
//


//
// Forward declarations
//
unsigned long bitfield_set(unsigned long *bf, int base, int length, unsigned long value);
unsigned long bitfield_get(unsigned long bf, int base, int length);