73 lines
2.0 KiB
C
73 lines
2.0 KiB
C
//
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// bitfield.h - extract and set bit fields
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//
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// Written by Eryk Vershen
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//
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// Bitfields are not particularly transportable between big and little
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// endian machines. Big endian machines lay out bitfields starting
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// from the most significant bit of the (one, two or four byte) number,
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// whereas little endian machines lay out bitfields starting from the
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// least signifcant bit.
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//
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// These routines were written to support some bitfields in a disk
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// data structure (partition map) whose original definition was on
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// a big-endian machine.
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//
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// They only work on 32-bit values because I didn't need 16-bit support.
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// The bits in the long word are numbered from 0 (least significant) to
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// 31 (most significant).
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//
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/*
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* Copyright 1996,1998 by Apple Computer, Inc.
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* All Rights Reserved
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*
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* Permission to use, copy, modify, and distribute this software and
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* its documentation for any purpose and without fee is hereby granted,
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* provided that the above copyright notice appears in all copies and
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* that both the copyright notice and this permission notice appear in
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* supporting documentation.
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*
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* APPLE COMPUTER DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
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* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
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* FOR A PARTICULAR PURPOSE.
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*
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* IN NO EVENT SHALL APPLE COMPUTER BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
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* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
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* LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
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* NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
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* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*/
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#ifndef __bitfield__
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#define __bitfield__
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//
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// Defines
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//
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//
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// Types
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//
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//
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// Global Constants
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//
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//
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// Global Variables
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//
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//
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// Forward declarations
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//
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unsigned long bitfield_set(unsigned long *bf, int base, int length, unsigned long value);
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unsigned long bitfield_get(unsigned long bf, int base, int length);
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#endif /* __bitfield__ */
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