1 /* $NetBSD: db_access.c,v 1.19 2009/03/07 22:02:17 ad Exp $ */ 2 3 /* 4 * Mach Operating System 5 * Copyright (c) 1991,1990 Carnegie Mellon University 6 * All Rights Reserved. 7 * 8 * Permission to use, copy, modify and distribute this software and its 9 * documentation is hereby granted, provided that both the copyright 10 * notice and this permission notice appear in all copies of the 11 * software, derivative works or modified versions, and any portions 12 * thereof, and that both notices appear in supporting documentation. 13 * 14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND FOR 16 * ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 17 * 18 * Carnegie Mellon requests users of this software to return to 19 * 20 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 21 * School of Computer Science 22 * Carnegie Mellon University 23 * Pittsburgh PA 15213-3890 24 * 25 * any improvements or extensions that they make and grant Carnegie the 26 * rights to redistribute these changes. 27 * 28 * Author: David B. Golub, Carnegie Mellon University 29 * Date: 7/90 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: db_access.c,v 1.19 2009/03/07 22:02:17 ad Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/proc.h> 37 #include <sys/endian.h> 38 39 #include <ddb/ddb.h> 40 41 /* 42 * Access unaligned data items on aligned (longword) 43 * boundaries. 44 */ 45 46 const int db_extend[] = { /* table for sign-extending */ 47 0, 48 0xFFFFFF80, 49 0xFFFF8000, 50 0xFF800000 51 }; 52 53 db_expr_t 54 db_get_value(db_addr_t addr, size_t size, bool is_signed) 55 { 56 char data[sizeof(db_expr_t)]; 57 db_expr_t value; 58 size_t i; 59 60 db_read_bytes(addr, size, data); 61 62 value = 0; 63 #if BYTE_ORDER == LITTLE_ENDIAN 64 for (i = size; i-- > 0;) 65 #else /* BYTE_ORDER == BIG_ENDIAN */ 66 for (i = 0; i < size; i++) 67 #endif /* BYTE_ORDER */ 68 value = (value << 8) + (data[i] & 0xFF); 69 70 if (size < 4 && is_signed && (value & db_extend[size]) != 0) 71 value |= db_extend[size]; 72 return (value); 73 } 74 75 void 76 db_put_value(db_addr_t addr, size_t size, db_expr_t value) 77 { 78 char data[sizeof(db_expr_t)]; 79 size_t i; 80 81 #if BYTE_ORDER == LITTLE_ENDIAN 82 for (i = 0; i < size; i++) 83 #else /* BYTE_ORDER == BIG_ENDIAN */ 84 for (i = size; i-- > 0;) 85 #endif /* BYTE_ORDER */ 86 { 87 data[i] = value & 0xFF; 88 value >>= 8; 89 } 90 91 db_write_bytes(addr, size, data); 92 } 93 94 void * 95 db_read_ptr(const char *name) 96 { 97 db_expr_t val; 98 void *p; 99 100 if (!db_value_of_name(name, &val)) { 101 db_printf("db_read_ptr: cannot find `%s'\n", name); 102 db_error(NULL); 103 /* NOTREACHED */ 104 } 105 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p); 106 return p; 107 } 108 109 int 110 db_read_int(const char *name) 111 { 112 db_expr_t val; 113 int p; 114 115 if (!db_value_of_name(name, &val)) { 116 db_printf("db_read_int: cannot find `%s'\n", name); 117 db_error(NULL); 118 /* NOTREACHED */ 119 } 120 db_read_bytes((db_addr_t)val, sizeof(p), (char *)&p); 121 return p; 122 } 123