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 * Author: David B. Golub, Carnegie Mellon University 27 * Date: 7/90 28 * $Id: db_access.c,v 1.4 1994/01/31 23:55:06 mycroft Exp $ 29 */ 30 31 #include <sys/param.h> 32 #include <sys/proc.h> 33 34 #include <machine/db_machdep.h> /* type definitions */ 35 36 /* 37 * Access unaligned data items on aligned (longword) 38 * boundaries. 39 */ 40 41 extern void db_read_bytes(); /* machine-dependent */ 42 extern void db_write_bytes(); /* machine-dependent */ 43 44 int db_extend[] = { /* table for sign-extending */ 45 0, 46 0xFFFFFF80, 47 0xFFFF8000, 48 0xFF800000 49 }; 50 51 db_expr_t 52 db_get_value(addr, size, is_signed) 53 db_addr_t addr; 54 register int size; 55 boolean_t is_signed; 56 { 57 char data[sizeof(int)]; 58 register db_expr_t value; 59 register int i; 60 61 db_read_bytes(addr, size, data); 62 63 value = 0; 64 #ifdef BYTE_MSF 65 for (i = 0; i < size; i++) 66 #else /* BYTE_LSF */ 67 for (i = size - 1; i >= 0; i--) 68 #endif 69 { 70 value = (value << 8) + (data[i] & 0xFF); 71 } 72 73 if (size < 4) { 74 if (is_signed && (value & db_extend[size]) != 0) 75 value |= db_extend[size]; 76 } 77 return (value); 78 } 79 80 void 81 db_put_value(addr, size, value) 82 db_addr_t addr; 83 register int size; 84 register db_expr_t value; 85 { 86 char data[sizeof(int)]; 87 register int i; 88 89 #ifdef BYTE_MSF 90 for (i = size - 1; i >= 0; i--) 91 #else /* BYTE_LSF */ 92 for (i = 0; i < size; i++) 93 #endif 94 { 95 data[i] = value & 0xFF; 96 value >>= 8; 97 } 98 99 db_write_bytes(addr, size, data); 100 } 101 102