bitfield.h

//
// 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. 
 */

#ifndef bitfield_h
#define bitfield_h

#include <stdint.h>

uint32_t bitfield_set(uint32_t *bf, int base, int length, uint32_t value);
uint32_t bitfield_get(uint32_t bf, int base, int length);

#endif