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15637ed4 RG |
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. | |
15637ed4 | 25 | * |
fde1aeb2 | 26 | * $Id: db_access.c,v 1.3 1993/11/25 01:30:01 wollman Exp $ |
15637ed4 | 27 | */ |
cbeffc91 | 28 | |
15637ed4 RG |
29 | /* |
30 | * Author: David B. Golub, Carnegie Mellon University | |
31 | * Date: 7/90 | |
32 | */ | |
33 | #include "param.h" | |
fde1aeb2 | 34 | #include "systm.h" |
15637ed4 | 35 | #include "proc.h" |
fde1aeb2 | 36 | #include "ddb/ddb.h" |
15637ed4 RG |
37 | |
38 | /* | |
39 | * Access unaligned data items on aligned (longword) | |
40 | * boundaries. | |
41 | */ | |
42 | ||
43 | extern void db_read_bytes(); /* machine-dependent */ | |
44 | extern void db_write_bytes(); /* machine-dependent */ | |
45 | ||
4c45483e | 46 | unsigned db_extend[] = { /* table for sign-extending */ |
15637ed4 | 47 | 0, |
4c45483e GW |
48 | 0xFFFFFF80U, |
49 | 0xFFFF8000U, | |
50 | 0xFF800000U | |
15637ed4 RG |
51 | }; |
52 | ||
53 | db_expr_t | |
54 | db_get_value(addr, size, is_signed) | |
55 | db_addr_t addr; | |
56 | register int size; | |
57 | boolean_t is_signed; | |
58 | { | |
59 | char data[sizeof(int)]; | |
60 | register db_expr_t value; | |
61 | register int i; | |
62 | ||
63 | db_read_bytes(addr, size, data); | |
64 | ||
65 | value = 0; | |
66 | #if BYTE_MSF | |
67 | for (i = 0; i < size; i++) | |
68 | #else /* BYTE_LSF */ | |
69 | for (i = size - 1; i >= 0; i--) | |
70 | #endif | |
71 | { | |
72 | value = (value << 8) + (data[i] & 0xFF); | |
73 | } | |
74 | ||
75 | if (size < 4) { | |
76 | if (is_signed && (value & db_extend[size]) != 0) | |
77 | value |= db_extend[size]; | |
78 | } | |
79 | return (value); | |
80 | } | |
81 | ||
82 | void | |
83 | db_put_value(addr, size, value) | |
84 | db_addr_t addr; | |
85 | register int size; | |
86 | register db_expr_t value; | |
87 | { | |
88 | char data[sizeof(int)]; | |
89 | register int i; | |
90 | ||
91 | #if BYTE_MSF | |
92 | for (i = size - 1; i >= 0; i--) | |
93 | #else /* BYTE_LSF */ | |
94 | for (i = 0; i < size; i++) | |
95 | #endif | |
96 | { | |
97 | data[i] = value & 0xFF; | |
98 | value >>= 8; | |
99 | } | |
100 | ||
101 | db_write_bytes(addr, size, data); | |
102 | } | |
103 |