FreeBSD/Linux Kernel Cross Reference
sys/ddb/db_access.c
1 /*-
2 * Mach Operating System
3 * Copyright (c) 1991,1990 Carnegie Mellon University
4 * All Rights Reserved.
5 *
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.
11 *
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.
15 *
16 * Carnegie Mellon requests users of this software to return to
17 *
18 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
19 * School of Computer Science
20 * Carnegie Mellon University
21 * Pittsburgh PA 15213-3890
22 *
23 * any improvements or extensions that they make and grant Carnegie the
24 * rights to redistribute these changes.
25 */
26 /*
27 * Author: David B. Golub, Carnegie Mellon University
28 * Date: 7/90
29 */
30
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD: src/sys/ddb/db_access.c,v 1.20 2005/12/04 02:12:39 ru Exp $");
33
34 #include <sys/param.h>
35 #include <sys/kdb.h>
36
37 #include <ddb/ddb.h>
38 #include <ddb/db_access.h>
39
40 /*
41 * Access unaligned data items on aligned (longword)
42 * boundaries.
43 */
44
45 static unsigned db_extend[] = { /* table for sign-extending */
46 0,
47 0xFFFFFF80U,
48 0xFFFF8000U,
49 0xFF800000U
50 };
51
52 #ifndef BYTE_MSF
53 #define BYTE_MSF 0
54 #endif
55
56 db_expr_t
57 db_get_value(addr, size, is_signed)
58 db_addr_t addr;
59 register int size;
60 boolean_t is_signed;
61 {
62 char data[sizeof(u_int64_t)];
63 register db_expr_t value;
64 register int i;
65
66 if (db_read_bytes(addr, size, data) != 0) {
67 db_printf("*** error reading from address %llx ***\n",
68 (long long)addr);
69 kdb_reenter();
70 }
71
72 value = 0;
73 #if BYTE_MSF
74 for (i = 0; i < size; i++)
75 #else /* BYTE_LSF */
76 for (i = size - 1; i >= 0; i--)
77 #endif
78 {
79 value = (value << 8) + (data[i] & 0xFF);
80 }
81
82 if (size < 4) {
83 if (is_signed && (value & db_extend[size]) != 0)
84 value |= db_extend[size];
85 }
86 return (value);
87 }
88
89 void
90 db_put_value(addr, size, value)
91 db_addr_t addr;
92 register int size;
93 register db_expr_t value;
94 {
95 char data[sizeof(int)];
96 register int i;
97
98 #if BYTE_MSF
99 for (i = size - 1; i >= 0; i--)
100 #else /* BYTE_LSF */
101 for (i = 0; i < size; i++)
102 #endif
103 {
104 data[i] = value & 0xFF;
105 value >>= 8;
106 }
107
108 if (db_write_bytes(addr, size, data) != 0) {
109 db_printf("*** error writing to address %llx ***\n",
110 (long long)addr);
111 kdb_reenter();
112 }
113 }
114
|