1 /*- 2 * SPDX-License-Identifier: MIT-CMU 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 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 /* 29 * Author: David B. Golub, Carnegie Mellon University 30 * Date: 7/90 31 */ 32 33 #include <sys/cdefs.h> 34 __FBSDID("$FreeBSD$"); 35 36 #include <sys/param.h> 37 #include <sys/kdb.h> 38 39 #include <ddb/ddb.h> 40 #include <ddb/db_access.h> 41 42 /* 43 * Access unaligned data items on aligned (longword) 44 * boundaries. 45 */ 46 47 static unsigned db_extend[] = { /* table for sign-extending */ 48 0, 49 0xFFFFFF80U, 50 0xFFFF8000U, 51 0xFF800000U 52 }; 53 54 #ifndef BYTE_MSF 55 #define BYTE_MSF 0 56 #endif 57 58 db_expr_t 59 db_get_value(db_addr_t addr, int size, bool is_signed) 60 { 61 char data[sizeof(u_int64_t)]; 62 db_expr_t value; 63 int i; 64 65 if (db_read_bytes(addr, size, data) != 0) { 66 db_printf("*** error reading from address %llx ***\n", 67 (long long)addr); 68 kdb_reenter(); 69 } 70 71 value = 0; 72 #if BYTE_MSF 73 for (i = 0; i < size; i++) 74 #else /* BYTE_LSF */ 75 for (i = size - 1; i >= 0; i--) 76 #endif 77 { 78 value = (value << 8) + (data[i] & 0xFF); 79 } 80 81 if (size < 4) { 82 if (is_signed && (value & db_extend[size]) != 0) 83 value |= db_extend[size]; 84 } 85 return (value); 86 } 87 88 void 89 db_put_value(db_addr_t addr, int size, db_expr_t value) 90 { 91 char data[sizeof(int)]; 92 int i; 93 94 #if BYTE_MSF 95 for (i = size - 1; i >= 0; i--) 96 #else /* BYTE_LSF */ 97 for (i = 0; i < size; i++) 98 #endif 99 { 100 data[i] = value & 0xFF; 101 value >>= 8; 102 } 103 104 if (db_write_bytes(addr, size, data) != 0) { 105 db_printf("*** error writing to address %llx ***\n", 106 (long long)addr); 107 kdb_reenter(); 108 } 109 } 110