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 * $Id: db_access.c,v 1.2 1993/05/20 03:39:04 cgd Exp $ 28 * 29 * HISTORY 30 * $Log: db_access.c,v $ 31 * Revision 1.2 1993/05/20 03:39:04 cgd 32 * add explicit rcs id 33 * 34 * Revision 1.1 1993/03/21 09:46:24 cgd 35 * Initial revision 36 * 37 * Revision 1.1 1992/03/25 21:44:50 pace 38 * Initial revision 39 * 40 * Revision 2.3 91/02/05 17:05:44 mrt 41 * Changed to new Mach copyright 42 * [91/01/31 16:16:22 mrt] 43 * 44 * Revision 2.2 90/08/27 21:48:20 dbg 45 * Fix type declarations. 46 * [90/08/07 dbg] 47 * Created. 48 * [90/07/25 dbg] 49 * 50 */ 51 /* 52 * Author: David B. Golub, Carnegie Mellon University 53 * Date: 7/90 54 */ 55 #include "param.h" 56 #include "proc.h" 57 #include <machine/db_machdep.h> /* type definitions */ 58 59 /* 60 * Access unaligned data items on aligned (longword) 61 * boundaries. 62 */ 63 64 extern void db_read_bytes(); /* machine-dependent */ 65 extern void db_write_bytes(); /* machine-dependent */ 66 67 int db_extend[] = { /* table for sign-extending */ 68 0, 69 0xFFFFFF80, 70 0xFFFF8000, 71 0xFF800000 72 }; 73 74 db_expr_t 75 db_get_value(addr, size, is_signed) 76 db_addr_t addr; 77 register int size; 78 boolean_t is_signed; 79 { 80 char data[sizeof(int)]; 81 register db_expr_t value; 82 register int i; 83 84 db_read_bytes(addr, size, data); 85 86 value = 0; 87 #if BYTE_MSF 88 for (i = 0; i < size; i++) 89 #else /* BYTE_LSF */ 90 for (i = size - 1; i >= 0; i--) 91 #endif 92 { 93 value = (value << 8) + (data[i] & 0xFF); 94 } 95 96 if (size < 4) { 97 if (is_signed && (value & db_extend[size]) != 0) 98 value |= db_extend[size]; 99 } 100 return (value); 101 } 102 103 void 104 db_put_value(addr, size, value) 105 db_addr_t addr; 106 register int size; 107 register db_expr_t value; 108 { 109 char data[sizeof(int)]; 110 register int i; 111 112 #if BYTE_MSF 113 for (i = size - 1; i >= 0; i--) 114 #else /* BYTE_LSF */ 115 for (i = 0; i < size; i++) 116 #endif 117 { 118 data[i] = value & 0xFF; 119 value >>= 8; 120 } 121 122 db_write_bytes(addr, size, data); 123 } 124 125