db_access.c revision 153072
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 * Author: David B. Golub, Carnegie Mellon University 28 * Date: 7/90 29 */ 30 31#include <sys/cdefs.h> 32__FBSDID("$FreeBSD: head/sys/ddb/db_access.c 153072 2005-12-04 02:12:43Z ru $"); 33 34#include <sys/param.h> 35#include <sys/kdb.h> 36 37#include <ddb/ddb.h> 38#include <ddb/db_access.h> 39 40/* 41 * Access unaligned data items on aligned (longword) 42 * boundaries. 43 */ 44 45static unsigned db_extend[] = { /* table for sign-extending */ 46 0, 47 0xFFFFFF80U, 48 0xFFFF8000U, 49 0xFF800000U 50}; 51 52#ifndef BYTE_MSF 53#define BYTE_MSF 0 54#endif 55 56db_expr_t 57db_get_value(addr, size, is_signed) 58 db_addr_t addr; 59 register int size; 60 boolean_t is_signed; 61{ 62 char data[sizeof(u_int64_t)]; 63 register db_expr_t value; 64 register int i; 65 66 if (db_read_bytes(addr, size, data) != 0) { 67 db_printf("*** error reading from address %llx ***\n", 68 (long long)addr); 69 kdb_reenter(); 70 } 71 72 value = 0; 73#if BYTE_MSF 74 for (i = 0; i < size; i++) 75#else /* BYTE_LSF */ 76 for (i = size - 1; i >= 0; i--) 77#endif 78 { 79 value = (value << 8) + (data[i] & 0xFF); 80 } 81 82 if (size < 4) { 83 if (is_signed && (value & db_extend[size]) != 0) 84 value |= db_extend[size]; 85 } 86 return (value); 87} 88 89void 90db_put_value(addr, size, value) 91 db_addr_t addr; 92 register int size; 93 register db_expr_t value; 94{ 95 char data[sizeof(int)]; 96 register int i; 97 98#if BYTE_MSF 99 for (i = size - 1; i >= 0; i--) 100#else /* BYTE_LSF */ 101 for (i = 0; i < size; i++) 102#endif 103 { 104 data[i] = value & 0xFF; 105 value >>= 8; 106 } 107 108 if (db_write_bytes(addr, size, data) != 0) { 109 db_printf("*** error writing to address %llx ***\n", 110 (long long)addr); 111 kdb_reenter(); 112 } 113} 114