93 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			93 lines
		
	
	
		
			2.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Mach Operating System
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 * Copyright (c) 1991,1990 Carnegie Mellon University
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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 its
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 * documentation is hereby granted, provided that both the copyright
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 * notice and this permission notice appear in all copies of the
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 * software, derivative works or modified versions, and any portions
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 * thereof, and that both notices appear in supporting documentation.
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 *
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 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
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 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
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 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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 *
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 * Carnegie Mellon requests users of this software to return to
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 *
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 *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
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 *  School of Computer Science
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 *  Carnegie Mellon University
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 *  Pittsburgh PA 15213-3890
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 *
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 * any improvements or extensions that they make and grant Carnegie the
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 * rights to redistribute these changes.
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 *
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 *	$Id: db_access.c,v 1.1 2003/01/15 21:50:58 mikesw Exp $
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 */
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/*
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 *	Author: David B. Golub, Carnegie Mellon University
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 *	Date:	7/90
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 */
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#include "ddb.h"
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#include "db_access.h"
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#include "extra.h"
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/*
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 * Access unaligned data items on aligned (longword)
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 * boundaries.
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 */
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static unsigned db_extend[] = {	/* table for sign-extending */
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	0,
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	0xFFFFFF80U,
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	0xFFFF8000U,
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	0xFF800000U
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};
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void
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db_read_bytes(addr, size, data)
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	vm_offset_t	addr;
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	register int	size;
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	register char	*data;
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{
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	register char	*src;
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	src = (char *)addr;
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	while (--size >= 0)
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	    *data++ = text_read_ub(src++);
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}
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db_expr_t
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db_get_value(addr, size, is_signed)
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	db_addr_t	addr;
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	register int	size;
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	boolean_t	is_signed;
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{
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	char		data[sizeof(int)];
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	register db_expr_t value;
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	register int	i;
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	db_read_bytes(addr, size, data);
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	value = 0;
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#if	BYTE_MSF
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	for (i = 0; i < size; i++)
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#else	/* BYTE_LSF */
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	for (i = size - 1; i >= 0; i--)
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#endif
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	{
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	    value = (value << 8) + (data[i] & 0xFF);
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	}
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	if (size < 4) {
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	    if (is_signed && (value & db_extend[size]) != 0)
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		value |= db_extend[size];
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	}
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	return (value);
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}
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