2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
6 * Permission to use, copy, modify and distribute this software and its
7 * documentation is hereby granted, provided that both the copyright
8 * notice and this permission notice appear in all copies of the
9 * software, derivative works or modified versions, and any portions
10 * thereof, and that both notices appear in supporting documentation.
12 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
13 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
14 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
16 * Carnegie Mellon requests users of this software to return to
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
26 * $FreeBSD: src/sys/ddb/db_access.c,v 1.15 1999/08/28 00:41:04 peter Exp $
27 * $DragonFly: src/sys/ddb/db_access.c,v 1.4 2005/12/23 21:35:44 swildner Exp $
31 * Author: David B. Golub, Carnegie Mellon University
34 #include <sys/param.h>
37 #include <ddb/db_access.h>
40 * Access unaligned data items on aligned (longword)
44 static unsigned db_extend[] = { /* table for sign-extending */
52 db_get_value(db_addr_t addr, int size, boolean_t is_signed)
54 char data[sizeof(int)];
58 db_read_bytes(addr, size, data);
62 for (i = 0; i < size; i++)
64 for (i = size - 1; i >= 0; i--)
67 value = (value << 8) + (data[i] & 0xFF);
71 if (is_signed && (value & db_extend[size]) != 0)
72 value |= db_extend[size];
78 db_put_value(db_addr_t addr, int size, db_expr_t value)
80 char data[sizeof(int)];
84 for (i = size - 1; i >= 0; i--)
86 for (i = 0; i < size; i++)
89 data[i] = value & 0xFF;
93 db_write_bytes(addr, size, data);