v7fs_endian.c revision 1.1
1 /* $NetBSD: v7fs_endian.c,v 1.1 2011/06/27 11:52:24 uch Exp $ */ 2 3 /*- 4 * Copyright (c) 2011 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by UCHIYAMA Yasushi. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: v7fs_endian.c,v 1.1 2011/06/27 11:52:24 uch Exp $"); 34 #if defined _KERNEL_OPT 35 #include "opt_v7fs.h" 36 #endif 37 38 #include "v7fs.h" 39 #include "v7fs_endian.h" 40 #include "v7fs_impl.h" 41 42 #ifndef BYTE_ORDER 43 #error 44 #endif 45 46 /* PDP to Little */ 47 #define bswap32pdp_le(x) \ 48 ((uint32_t) \ 49 ((((x) & 0xffff0000) >> 16) | \ 50 (((x) & 0x0000ffff) << 16))) 51 /* PDP to Big */ 52 #define bswap32pdp_be(x) \ 53 ((uint32_t) \ 54 ((((x) & 0xff00ff00) >> 8) | \ 55 (((x) & 0x00ff00ff) << 8))) 56 #ifdef V7FS_EI 57 static uint32_t val32_normal_order(uint32_t); 58 static uint32_t val32_reverse_order(uint32_t); 59 #if BYTE_ORDER == LITTLE_ENDIAN 60 static uint32_t val32_pdp_to_little(uint32_t); 61 #else 62 static uint32_t val32_pdp_to_big(uint32_t); 63 #endif 64 static uint16_t val16_normal_order(uint16_t); 65 static uint16_t val16_reverse_order(uint16_t); 66 static v7fs_daddr_t val24_reverse_order_read(uint8_t *); 67 static void val24_reverse_order_write(v7fs_daddr_t, uint8_t *); 68 static v7fs_daddr_t val24_pdp_read(uint8_t *); 69 static void val24_pdp_write(v7fs_daddr_t, uint8_t *); 70 71 static uint32_t 72 val32_normal_order(uint32_t v) 73 { 74 75 return v; 76 } 77 78 static uint32_t 79 val32_reverse_order(uint32_t v) 80 { 81 82 return bswap32(v); 83 } 84 #if BYTE_ORDER == LITTLE_ENDIAN 85 static uint32_t 86 val32_pdp_to_little(uint32_t v) 87 { 88 89 return bswap32pdp_le(v); 90 } 91 #else 92 static uint32_t 93 val32_pdp_to_big(uint32_t v) 94 { 95 96 return bswap32pdp_be(v); 97 } 98 #endif 99 static uint16_t 100 val16_normal_order(uint16_t v) 101 { 102 103 return v; 104 } 105 106 static uint16_t 107 val16_reverse_order(uint16_t v) 108 { 109 110 return bswap16(v); 111 } 112 113 static v7fs_daddr_t 114 val24_reverse_order_read(uint8_t *a) 115 { 116 #if BYTE_ORDER == LITTLE_ENDIAN 117 return (a[0] << 16) | (a[1] << 8) | a[2]; 118 #else 119 return (a[2] << 16) | (a[1] << 8) | a[0]; 120 #endif 121 } 122 123 static void 124 val24_reverse_order_write(v7fs_daddr_t addr, uint8_t *a) 125 { 126 #if BYTE_ORDER == LITTLE_ENDIAN 127 a[0] = (addr >> 16) & 0xff; 128 a[1] = (addr >> 8) & 0xff; 129 a[2] = addr & 0xff; 130 #else 131 a[0] = addr & 0xff; 132 a[1] = (addr >> 8) & 0xff; 133 a[2] = (addr >> 16) & 0xff; 134 #endif 135 } 136 137 static v7fs_daddr_t 138 val24_pdp_read(uint8_t *a) 139 { 140 141 return (a[0] << 16) | a[1] | (a[2] << 8); 142 } 143 144 static void 145 val24_pdp_write(v7fs_daddr_t addr, uint8_t *a) 146 { 147 148 a[0] = (addr >> 16) & 0xff; 149 a[1] = addr & 0xff; 150 a[2] = (addr >> 8) & 0xff; 151 } 152 153 void 154 v7fs_endian_init(struct v7fs_self *fs) 155 { 156 struct endian_conversion_ops *ops = &fs->val; 157 158 switch (fs->endian) 159 { 160 #if BYTE_ORDER == LITTLE_ENDIAN 161 case LITTLE_ENDIAN: 162 ops->conv32 = val32_normal_order; 163 ops->conv16 = val16_normal_order; 164 ops->conv24read = val24_normal_order_read; 165 ops->conv24write = val24_normal_order_write; 166 break; 167 case BIG_ENDIAN: 168 ops->conv32 = val32_reverse_order; 169 ops->conv16 = val16_reverse_order; 170 ops->conv24read = val24_reverse_order_read; 171 ops->conv24write = val24_reverse_order_write; 172 break; 173 case PDP_ENDIAN: 174 ops->conv32 = val32_pdp_to_little; 175 ops->conv16 = val16_normal_order; 176 ops->conv24read = val24_pdp_read; 177 ops->conv24write = val24_pdp_write; 178 break; 179 #else /* BIG_ENDIAN */ 180 case LITTLE_ENDIAN: 181 ops->conv32 = val32_reverse_order; 182 ops->conv16 = val16_reverse_order; 183 ops->conv24read = val24_reverse_order_read; 184 ops->conv24write = val24_reverse_order_write; 185 break; 186 case BIG_ENDIAN: 187 ops->conv32 = val32_normal_order; 188 ops->conv16 = val16_normal_order; 189 ops->conv24read = val24_normal_order_read; 190 ops->conv24write = val24_normal_order_write; 191 break; 192 case PDP_ENDIAN: 193 ops->conv32 = val32_pdp_to_big; 194 ops->conv16 = val16_reverse_order; 195 ops->conv24read = val24_pdp_read; 196 ops->conv24write = val24_pdp_write; 197 break; 198 #endif 199 } 200 } 201 #endif /* V7FS_EI */ 202 v7fs_daddr_t 203 val24_normal_order_read(uint8_t *a) 204 { 205 /*(v7fs_daddr_t)cast is required for int 16bit system. */ 206 #if BYTE_ORDER == LITTLE_ENDIAN 207 return ((v7fs_daddr_t)a[2] << 16) | ((v7fs_daddr_t)a[1] << 8) | 208 (v7fs_daddr_t)a[0]; 209 #else 210 return ((v7fs_daddr_t)a[0] << 16) | ((v7fs_daddr_t)a[1] << 8) | 211 (v7fs_daddr_t)a[2]; 212 #endif 213 } 214 215 void 216 val24_normal_order_write(v7fs_daddr_t addr, uint8_t *a) 217 { 218 #if BYTE_ORDER == LITTLE_ENDIAN 219 a[0] = addr & 0xff; 220 a[1] = (addr >> 8) & 0xff; 221 a[2] = (addr >> 16) & 0xff; 222 #else 223 a[0] = (addr >> 16) & 0xff; 224 a[1] = (addr >> 8) & 0xff; 225 a[2] = addr & 0xff; 226 #endif 227 } 228
Indexes created Mon Sep 22 21:09:42 GMT 2025