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 #include <sys/endian.h> 39 40 #include <ddb/ddb.h> 41 #include <ddb/db_access.h> 42 43 /* 44 * Access unaligned data items on aligned (longword) 45 * boundaries. 46 */ 47 48 static unsigned db_extend[] = { /* table for sign-extending */ 49 0, 50 0xFFFFFF80U, 51 0xFFFF8000U, 52 0xFF800000U 53 }; 54 55 db_expr_t 56 db_get_value(db_addr_t addr, int size, bool is_signed) 57 { 58 char data[sizeof(uint64_t)]; 59 db_expr_t value; 60 int i; 61 62 if (db_read_bytes(addr, size, data) != 0) { 63 db_printf("*** error reading from address %llx ***\n", 64 (long long)addr); 65 kdb_reenter(); 66 } 67 68 value = 0; 69 #if _BYTE_ORDER == _BIG_ENDIAN 70 for (i = 0; i < size; i++) 71 #else /* _LITTLE_ENDIAN */ 72 for (i = size - 1; i >= 0; i--) 73 #endif 74 { 75 value = (value << 8) + (data[i] & 0xFF); 76 } 77 78 if (size < 4) { 79 if (is_signed && (value & db_extend[size]) != 0) 80 value |= db_extend[size]; 81 } 82 return (value); 83 } 84 85 void 86 db_put_value(db_addr_t addr, int size, db_expr_t value) 87 { 88 char data[sizeof(int)]; 89 int i; 90 91 #if _BYTE_ORDER == _BIG_ENDIAN 92 for (i = size - 1; i >= 0; i--) 93 #else /* _LITTLE_ENDIAN */ 94 for (i = 0; i < size; i++) 95 #endif 96 { 97 data[i] = value & 0xFF; 98 value >>= 8; 99 } 100 101 if (db_write_bytes(addr, size, data) != 0) { 102 db_printf("*** error writing to address %llx ***\n", 103 (long long)addr); 104 kdb_reenter(); 105 } 106 } 107