projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 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. | |
| 25 | */ | |
| 26 | /* | |
| 27 | * HISTORY | |
| 28 | * $Log: db_access.c,v $ | |
| 29 | * Revision 1.1 1992/03/25 21:44:50 pace | |
| 30 | * Initial revision | |
| 31 | * | |
| 32 | * Revision 2.3 91/02/05 17:05:44 mrt | |
| 33 | * Changed to new Mach copyright | |
| 34 | * [91/01/31 16:16:22 mrt] | |
| 35 | * | |
| 36 | * Revision 2.2 90/08/27 21:48:20 dbg | |
| 37 | * Fix type declarations. | |
| 38 | * [90/08/07 dbg] | |
| 39 | * Created. | |
| 40 | * [90/07/25 dbg] | |
| 41 | * | |
| 42 | */ | |
| 43 | /* | |
| 44 | * Author: David B. Golub, Carnegie Mellon University | |
| 45 | * Date: 7/90 | |
| 46 | */ | |
| 47 | #include "param.h" | |
| 48 | #include "proc.h" | |
| 49 | #include <machine/db_machdep.h> /* type definitions */ | |
| 50 | ||
| 51 | /* | |
| 52 | * Access unaligned data items on aligned (longword) | |
| 53 | * boundaries. | |
| 54 | */ | |
| 55 | ||
| 56 | extern void db_read_bytes(); /* machine-dependent */ | |
| 57 | extern void db_write_bytes(); /* machine-dependent */ | |
| 58 | ||
| 59 | int db_extend[] = { /* table for sign-extending */ | |
| 60 | 0, | |
| 61 | 0xFFFFFF80, | |
| 62 | 0xFFFF8000, | |
| 63 | 0xFF800000 | |
| 64 | }; | |
| 65 | ||
| 66 | db_expr_t | |
| 67 | db_get_value(addr, size, is_signed) | |
| 68 | db_addr_t addr; | |
| 69 | register int size; | |
| 70 | boolean_t is_signed; | |
| 71 | { | |
| 72 | char data[sizeof(int)]; | |
| 73 | register db_expr_t value; | |
| 74 | register int i; | |
| 75 | ||
| 76 | db_read_bytes(addr, size, data); | |
| 77 | ||
| 78 | value = 0; | |
| 79 | #if BYTE_MSF | |
| 80 | for (i = 0; i < size; i++) | |
| 81 | #else /* BYTE_LSF */ | |
| 82 | for (i = size - 1; i >= 0; i--) | |
| 83 | #endif | |
| 84 | { | |
| 85 | value = (value << 8) + (data[i] & 0xFF); | |
| 86 | } | |
| 87 | ||
| 88 | if (size < 4) { | |
| 89 | if (is_signed && (value & db_extend[size]) != 0) | |
| 90 | value |= db_extend[size]; | |
| 91 | } | |
| 92 | return (value); | |
| 93 | } | |
| 94 | ||
| 95 | void | |
| 96 | db_put_value(addr, size, value) | |
| 97 | db_addr_t addr; | |
| 98 | register int size; | |
| 99 | register db_expr_t value; | |
| 100 | { | |
| 101 | char data[sizeof(int)]; | |
| 102 | register int i; | |
| 103 | ||
| 104 | #if BYTE_MSF | |
| 105 | for (i = size - 1; i >= 0; i--) | |
| 106 | #else /* BYTE_LSF */ | |
| 107 | for (i = 0; i < size; i++) | |
| 108 | #endif | |
| 109 | { | |
| 110 | data[i] = value & 0xFF; | |
| 111 | value >>= 8; | |
| 112 | } | |
| 113 | ||
| 114 | db_write_bytes(addr, size, data); | |
| 115 | } | |
| 116 |