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