libkern/libkern/machine/OSByteOrder.h

   1 /*
   2  * Copyright (c) 2000 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*
  23  * Copyright (c) 1999 Apple Computer, Inc.  All rights reserved.
  24  *
  25  * HISTORY
  26  *
  27  */
  28
  29
  30 #ifndef _OS_OSBYTEORDERMACHINE_H
  31 #define _OS_OSBYTEORDERMACHINE_H
  32
  33 #include <libkern/OSTypes.h>
  34
  35 /* Functions for byte reversed loads. */
  36
  37 OS_INLINE
  38 UInt16
  39 OSReadSwapInt16(
  40     volatile void               * base,
  41     UInt                          offset
  42 )
  43 {
  44     union sconv {
  45         UInt16 us;
  46         UInt8  uc[2];
  47     } *inp, outv;
  48     inp = (union sconv *)((UInt8 *)base + offset);
  49     outv.uc[0] = inp->uc[1];
  50     outv.uc[1] = inp->uc[0];
  51     return (outv.us);
  52 }
  53
  54 OS_INLINE
  55 UInt32
  56 OSReadSwapInt32(
  57     volatile void               * base,
  58     UInt                          offset
  59 )
  60 {
  61     union lconv {
  62         UInt32 ul;
  63         UInt8  uc[4];
  64     } *inp, outv;
  65     inp = (union lconv *)((UInt8 *)base + offset);
  66     outv.uc[0] = inp->uc[3];
  67     outv.uc[1] = inp->uc[2];
  68     outv.uc[2] = inp->uc[1];
  69     outv.uc[3] = inp->uc[0];
  70     return (outv.ul);
  71 }
  72
  73 OS_INLINE
  74 UInt64
  75 OSReadSwapInt64(
  76     volatile void               * base,
  77     UInt                          offset
  78 )
  79 {
  80     union llconv {
  81         UInt64 ull;
  82         UInt8  uc[8];
  83     } *inp, outv;
  84     inp = (union llconv *)((UInt8 *)base + offset);
  85     outv.uc[0] = inp->uc[7];
  86     outv.uc[1] = inp->uc[6];
  87     outv.uc[2] = inp->uc[5];
  88     outv.uc[3] = inp->uc[4];
  89     outv.uc[4] = inp->uc[3];
  90     outv.uc[5] = inp->uc[2];
  91     outv.uc[6] = inp->uc[1];
  92     outv.uc[7] = inp->uc[0];
  93     return (outv.ull);
  94 }
  95
  96 OS_INLINE
  97 UInt
  98 OSReadSwapInt(
  99     volatile void               * base,
 100     UInt                          offset
 101 )
 102 {
 103     return (UInt)OSReadSwapInt32(base, offset);
 104 }
 105
 106 /* Functions for byte reversed stores. */
 107
 108 OS_INLINE
 109 void
 110 OSWriteSwapInt16(
 111     volatile void               * base,
 112     UInt                          offset,
 113     UInt16                        data
 114 )
 115 {
 116     union sconv {
 117         UInt16 us;
 118         UInt8  uc[2];
 119     } *inp, *outp;
 120     inp  = (union sconv *)((UInt8 *)base + offset);
 121     outp = (union sconv *)&data;
 122     outp->uc[0] = inp->uc[1];
 123     outp->uc[1] = inp->uc[0];
 124 }
 125
 126 OS_INLINE
 127 void
 128 OSWriteSwapInt32(
 129     volatile void               * base,
 130     UInt                          offset,
 131     UInt32                        data
 132 )
 133 {
 134     union lconv {
 135         UInt32 ul;
 136         UInt8  uc[4];
 137     } *inp, *outp;
 138     inp  = (union lconv *)((UInt8 *)base + offset);
 139     outp = (union lconv *)&data;
 140     outp->uc[0] = inp->uc[3];
 141     outp->uc[1] = inp->uc[2];
 142     outp->uc[2] = inp->uc[1];
 143     outp->uc[3] = inp->uc[0];
 144 }
 145
 146 OS_INLINE
 147 void
 148 OSWriteSwapInt64(
 149     volatile void               * base,
 150     UInt                          offset,
 151     UInt64                        data
 152 )
 153 {
 154     union llconv {
 155         UInt64 ull;
 156         UInt8  uc[8];
 157     } *inp, *outp;
 158     inp = (union llconv *)((UInt8 *)base + offset);
 159     outp = (union llconv *)&data;
 160     outp->uc[0] = inp->uc[7];
 161     outp->uc[1] = inp->uc[6];
 162     outp->uc[2] = inp->uc[5];
 163     outp->uc[3] = inp->uc[4];
 164     outp->uc[4] = inp->uc[3];
 165     outp->uc[5] = inp->uc[2];
 166     outp->uc[6] = inp->uc[1];
 167     outp->uc[7] = inp->uc[0];
 168 }
 169
 170 OS_INLINE
 171 void
 172 OSWriteSwapInt(
 173     volatile void               * base,
 174     UInt                          offset,
 175     UInt                          data
 176 )
 177 {
 178     OSWriteSwapInt32(base, offset, (UInt32)data);
 179 }
 180
 181 /* Generic byte swapping functions. */
 182
 183 OS_INLINE
 184 UInt16
 185 OSSwapInt16(
 186     UInt16                        data
 187 )
 188 {
 189     UInt16 temp = data;
 190     return OSReadSwapInt16(&temp, 0);
 191 }
 192
 193 OS_INLINE
 194 UInt32
 195 OSSwapInt32(
 196     UInt32                        data
 197 )
 198 {
 199     UInt32 temp = data;
 200     return OSReadSwapInt32(&temp, 0);
 201 }
 202
 203 OS_INLINE
 204 UInt64
 205 OSSwapInt64(
 206     UInt64                        data
 207 )
 208 {
 209     UInt64 temp = data;
 210     return OSReadSwapInt64(&temp, 0);
 211 }
 212
 213 OS_INLINE
 214 UInt
 215 OSSwapInt(
 216     UInt                          data
 217 )
 218 {
 219     UInt temp = data;
 220     return OSReadSwapInt(&temp, 0);
 221 }
 222
 223 #endif /* ! _OS_OSBYTEORDERMACHINE_H */