1 /* $OpenBSD: db_access.c,v 1.6 1997/07/06 23:09:23 niklas Exp $ */ 2 /* $NetBSD: db_access.c,v 1.8 1994/10/09 08:37:35 mycroft Exp $ */ 3 4 /* 5 * Mach Operating System 6 * Copyright (c) 1991,1990 Carnegie Mellon University 7 * All Rights Reserved. 8 * 9 * Permission to use, copy, modify and distribute this software and its 10 * documentation is hereby granted, provided that both the copyright 11 * notice and this permission notice appear in all copies of the 12 * software, derivative works or modified versions, and any portions 13 * thereof, and that both notices appear in supporting documentation. 14 * 15 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS 16 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 17 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 18 * 19 * Carnegie Mellon requests users of this software to return to 20 * 21 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 22 * School of Computer Science 23 * Carnegie Mellon University 24 * Pittsburgh PA 15213-3890 25 * 26 * any improvements or extensions that they make and grant Carnegie the 27 * the rights to redistribute these changes. 28 * 29 * Author: David B. Golub, Carnegie Mellon University 30 * Date: 7/90 31 */ 32 33 #include <sys/param.h> 34 #include <sys/proc.h> 35 36 #include <machine/db_machdep.h> /* type definitions */ 37 #include <machine/endian.h> 38 39 #include <ddb/db_access.h> 40 41 /* 42 * Access unaligned data items on aligned (longword) 43 * boundaries. 44 */ 45 db_expr_t 46 db_get_value(addr, size, is_signed) 47 db_addr_t addr; 48 size_t size; 49 boolean_t is_signed; 50 { 51 char data[sizeof(db_expr_t)]; 52 db_expr_t value, extend; 53 int i; 54 55 db_read_bytes(addr, size, data); 56 57 value = 0; 58 extend = (~(db_expr_t)0) << (size * 8 - 1); 59 #if BYTE_ORDER == LITTLE_ENDIAN 60 for (i = size - 1; i >= 0; i--) 61 #else /* BYTE_ORDER == BIG_ENDIAN */ 62 for (i = 0; i < size; i++) 63 #endif /* BYTE_ORDER */ 64 value = (value << 8) + (data[i] & 0xFF); 65 66 if (size < sizeof(db_expr_t) && is_signed && (value & extend)) 67 value |= extend; 68 return (value); 69 } 70 71 void 72 db_put_value(addr, size, value) 73 db_addr_t addr; 74 register size_t size; 75 register db_expr_t value; 76 { 77 char data[sizeof(db_expr_t)]; 78 register int i; 79 80 #if BYTE_ORDER == LITTLE_ENDIAN 81 for (i = 0; i < size; i++) 82 #else /* BYTE_ORDER == BIG_ENDIAN */ 83 for (i = size - 1; i >= 0; i--) 84 #endif /* BYTE_ORDER */ 85 { 86 data[i] = value & 0xFF; 87 value >>= 8; 88 } 89 90 db_write_bytes(addr, size, data); 91 } 92