2 * SPDX-License-Identifier: MIT-CMU
4 * Mach Operating System
5 * Copyright (c) 1991,1990 Carnegie Mellon University
8 * Permission to use, copy, modify and distribute this software and its
9 * documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR
16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
18 * Carnegie Mellon requests users of this software to return to
20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
29 * Author: David B. Golub, Carnegie Mellon University
33 #include <sys/cdefs.h>
34 #include <sys/param.h>
36 #include <sys/endian.h>
39 #include <ddb/db_access.h>
42 * Access unaligned data items on aligned (longword)
46 static unsigned db_extend[] = { /* table for sign-extending */
54 db_get_value(db_addr_t addr, int size, bool is_signed)
56 char data[sizeof(uint64_t)];
60 if (db_read_bytes(addr, size, data) != 0) {
61 db_printf("*** error reading from address %llx ***\n",
67 #if _BYTE_ORDER == _BIG_ENDIAN
68 for (i = 0; i < size; i++)
69 #else /* _LITTLE_ENDIAN */
70 for (i = size - 1; i >= 0; i--)
73 value = (value << 8) + (data[i] & 0xFF);
77 if (is_signed && (value & db_extend[size]) != 0)
78 value |= db_extend[size];
84 db_put_value(db_addr_t addr, int size, db_expr_t value)
86 char data[sizeof(int)];
89 #if _BYTE_ORDER == _BIG_ENDIAN
90 for (i = size - 1; i >= 0; i--)
91 #else /* _LITTLE_ENDIAN */
92 for (i = 0; i < size; i++)
95 data[i] = value & 0xFF;
99 if (db_write_bytes(addr, size, data) != 0) {
100 db_printf("*** error writing to address %llx ***\n",