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/*
* Mach Operating System
* Copyright (c) 1991,1990 Carnegie Mellon University
* All Rights Reserved.
*
* Permission to use, copy, modify and distribute this software and its
* documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
* ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*
* HISTORY
* $Log: db_access.c,v $
* Revision 1.1 1992/03/25 21:44:50 pace
* Initial revision
*
* Revision 2.3 91/02/05 17:05:44 mrt
* Changed to new Mach copyright
* [91/01/31 16:16:22 mrt]
*
* Revision 2.2 90/08/27 21:48:20 dbg
* Fix type declarations.
* [90/08/07 dbg]
* Created.
* [90/07/25 dbg]
*
*/
/*
* Author: David B. Golub, Carnegie Mellon University
* Date: 7/90
*/
#include "param.h"
#include "proc.h"
#include <machine/db_machdep.h> /* type definitions */
/*
* Access unaligned data items on aligned (longword)
* boundaries.
*/
extern void db_read_bytes(); /* machine-dependent */
extern void db_write_bytes(); /* machine-dependent */
int db_extend[] = { /* table for sign-extending */
0,
0xFFFFFF80,
0xFFFF8000,
0xFF800000
};
db_expr_t
db_get_value(addr, size, is_signed)
db_addr_t addr;
register int size;
boolean_t is_signed;
{
char data[sizeof(int)];
register db_expr_t value;
register int i;
db_read_bytes(addr, size, data);
value = 0;
#if BYTE_MSF
for (i = 0; i < size; i++)
#else /* BYTE_LSF */
for (i = size - 1; i >= 0; i--)
#endif
{
value = (value << 8) + (data[i] & 0xFF);
}
if (size < 4) {
if (is_signed && (value & db_extend[size]) != 0)
value |= db_extend[size];
}
return (value);
}
void
db_put_value(addr, size, value)
db_addr_t addr;
register int size;
register db_expr_t value;
{
char data[sizeof(int)];
register int i;
#if BYTE_MSF
for (i = size - 1; i >= 0; i--)
#else /* BYTE_LSF */
for (i = 0; i < size; i++)
#endif
{
data[i] = value & 0xFF;
value >>= 8;
}
db_write_bytes(addr, size, data);
}
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