1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
|
/*
LUFA Library
Copyright (C) Dean Camera, 2017.
dean [at] fourwalledcubicle [dot] com
www.lufa-lib.org
*/
/*
Copyright 2017 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby granted
without fee, provided that the above copyright notice appear in
all copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of the author not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
The author disclaims all warranties with regard to this
software, including all implied warranties of merchantability
and fitness. In no event shall the author be liable for any
special, indirect or consequential damages or any damages
whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortious action,
arising out of or in connection with the use or performance of
this software.
*/
/** \file
* \brief Endianness and Byte Ordering macros and functions.
*
* \copydetails Group_Endianness
*/
/** \ingroup Group_Endianness
* \defgroup Group_ByteSwapping Byte Reordering
* \brief Macros and functions for forced byte reordering.
*/
/** \ingroup Group_Endianness
* \defgroup Group_EndianConversion Endianness Conversion
* \brief Macros and functions for automatic endianness conversion.
*/
/** \ingroup Group_Common
* \defgroup Group_Endianness Endianness and Byte Ordering
* \brief Convenience macros and functions relating to byte (re-)ordering
*
* Common library convenience macros and functions relating to byte (re-)ordering.
*
* @{
*/
#ifndef __LUFA_ENDIANNESS_H__
#define __LUFA_ENDIANNESS_H__
/* Enable C linkage for C++ Compilers: */
#if defined(__cplusplus)
extern "C" {
#endif
/* Preprocessor Checks: */
#if !defined(__INCLUDE_FROM_COMMON_H)
#error Do not include this file directly. Include LUFA/Common/Common.h instead to gain this functionality.
#endif
#if !(defined(ARCH_BIG_ENDIAN) || defined(ARCH_LITTLE_ENDIAN))
#error ARCH_BIG_ENDIAN or ARCH_LITTLE_ENDIAN not set for the specified architecture.
#endif
/* Public Interface - May be used in end-application: */
/* Macros: */
/** Swaps the byte ordering of a 16-bit value at compile-time. Do not use this macro for swapping byte orderings
* of dynamic values computed at runtime, use \ref SwapEndian_16() instead. The result of this macro can be used
* inside struct or other variable initializers outside of a function, something that is not possible with the
* inline function variant.
*
* \hideinitializer
*
* \ingroup Group_ByteSwapping
*
* \param[in] x 16-bit value whose byte ordering is to be swapped.
*
* \return Input value with the byte ordering reversed.
*/
#define SWAPENDIAN_16(x) (uint16_t)((((x) & 0xFF00) >> 8) | (((x) & 0x00FF) << 8))
/** Swaps the byte ordering of a 32-bit value at compile-time. Do not use this macro for swapping byte orderings
* of dynamic values computed at runtime- use \ref SwapEndian_32() instead. The result of this macro can be used
* inside struct or other variable initializers outside of a function, something that is not possible with the
* inline function variant.
*
* \hideinitializer
*
* \ingroup Group_ByteSwapping
*
* \param[in] x 32-bit value whose byte ordering is to be swapped.
*
* \return Input value with the byte ordering reversed.
*/
#define SWAPENDIAN_32(x) (uint32_t)((((x) & 0xFF000000UL) >> 24UL) | (((x) & 0x00FF0000UL) >> 8UL) | \
(((x) & 0x0000FF00UL) << 8UL) | (((x) & 0x000000FFUL) << 24UL))
#if defined(ARCH_BIG_ENDIAN) && !defined(le16_to_cpu)
#define le16_to_cpu(x) SwapEndian_16(x)
#define le32_to_cpu(x) SwapEndian_32(x)
#define be16_to_cpu(x) (x)
#define be32_to_cpu(x) (x)
#define cpu_to_le16(x) SwapEndian_16(x)
#define cpu_to_le32(x) SwapEndian_32(x)
#define cpu_to_be16(x) (x)
#define cpu_to_be32(x) (x)
#define LE16_TO_CPU(x) SWAPENDIAN_16(x)
#define LE32_TO_CPU(x) SWAPENDIAN_32(x)
#define BE16_TO_CPU(x) (x)
#define BE32_TO_CPU(x) (x)
#define CPU_TO_LE16(x) SWAPENDIAN_16(x)
#define CPU_TO_LE32(x) SWAPENDIAN_32(x)
#define CPU_TO_BE16(x) (x)
#define CPU_TO_BE32(x) (x)
#elif !defined(le16_to_cpu)
/** \name Run-time endianness conversion */
//@{
/** Performs a conversion between a Little Endian encoded 16-bit piece of data and the
* Endianness of the currently selected CPU architecture.
*
* On little endian architectures, this macro does nothing.
*
* \note This macro is designed for run-time conversion of data - for compile-time endianness
* conversion, use \ref LE16_TO_CPU instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define le16_to_cpu(x) (x)
/** Performs a conversion between a Little Endian encoded 32-bit piece of data and the
* Endianness of the currently selected CPU architecture.
*
* On little endian architectures, this macro does nothing.
*
* \note This macro is designed for run-time conversion of data - for compile-time endianness
* conversion, use \ref LE32_TO_CPU instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define le32_to_cpu(x) (x)
/** Performs a conversion between a Big Endian encoded 16-bit piece of data and the
* Endianness of the currently selected CPU architecture.
*
* On big endian architectures, this macro does nothing.
*
* \note This macro is designed for run-time conversion of data - for compile-time endianness
* conversion, use \ref BE16_TO_CPU instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define be16_to_cpu(x) SwapEndian_16(x)
/** Performs a conversion between a Big Endian encoded 32-bit piece of data and the
* Endianness of the currently selected CPU architecture.
*
* On big endian architectures, this macro does nothing.
*
* \note This macro is designed for run-time conversion of data - for compile-time endianness
* conversion, use \ref BE32_TO_CPU instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define be32_to_cpu(x) SwapEndian_32(x)
/** Performs a conversion on a natively encoded 16-bit piece of data to ensure that it
* is in Little Endian format regardless of the currently selected CPU architecture.
*
* On little endian architectures, this macro does nothing.
*
* \note This macro is designed for run-time conversion of data - for compile-time endianness
* conversion, use \ref CPU_TO_LE16 instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define cpu_to_le16(x) (x)
/** Performs a conversion on a natively encoded 32-bit piece of data to ensure that it
* is in Little Endian format regardless of the currently selected CPU architecture.
*
* On little endian architectures, this macro does nothing.
*
* \note This macro is designed for run-time conversion of data - for compile-time endianness
* conversion, use \ref CPU_TO_LE32 instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define cpu_to_le32(x) (x)
/** Performs a conversion on a natively encoded 16-bit piece of data to ensure that it
* is in Big Endian format regardless of the currently selected CPU architecture.
*
* On big endian architectures, this macro does nothing.
*
* \note This macro is designed for run-time conversion of data - for compile-time endianness
* conversion, use \ref CPU_TO_BE16 instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define cpu_to_be16(x) SwapEndian_16(x)
/** Performs a conversion on a natively encoded 32-bit piece of data to ensure that it
* is in Big Endian format regardless of the currently selected CPU architecture.
*
* On big endian architectures, this macro does nothing.
*
* \note This macro is designed for run-time conversion of data - for compile-time endianness
* conversion, use \ref CPU_TO_BE32 instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define cpu_to_be32(x) SwapEndian_32(x)
//@}
/** \name Compile-time endianness conversion */
//@{
/** Performs a conversion between a Little Endian encoded 16-bit piece of data and the
* Endianness of the currently selected CPU architecture.
*
* On little endian architectures, this macro does nothing.
*
* \note This macro is designed for compile-time conversion of data - for run time endianness
* conversion, use \ref le16_to_cpu instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define LE16_TO_CPU(x) (x)
/** Performs a conversion between a Little Endian encoded 32-bit piece of data and the
* Endianness of the currently selected CPU architecture.
*
* On little endian architectures, this macro does nothing.
*
* \note This macro is designed for compile-time conversion of data - for run time endianness
* conversion, use \ref le32_to_cpu instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define LE32_TO_CPU(x) (x)
/** Performs a conversion between a Big Endian encoded 16-bit piece of data and the
* Endianness of the currently selected CPU architecture.
*
* On big endian architectures, this macro does nothing.
*
* \note This macro is designed for compile-time conversion of data - for run-time endianness
* conversion, use \ref be16_to_cpu instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define BE16_TO_CPU(x) SWAPENDIAN_16(x)
/** Performs a conversion between a Big Endian encoded 32-bit piece of data and the
* Endianness of the currently selected CPU architecture.
*
* On big endian architectures, this macro does nothing.
*
* \note This macro is designed for compile-time conversion of data - for run-time endianness
* conversion, use \ref be32_to_cpu instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define BE32_TO_CPU(x) SWAPENDIAN_32(x)
/** Performs a conversion on a natively encoded 16-bit piece of data to ensure that it
* is in Little Endian format regardless of the currently selected CPU architecture.
*
* On little endian architectures, this macro does nothing.
*
* \note This macro is designed for compile-time conversion of data - for run-time endianness
* conversion, use \ref cpu_to_le16 instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define CPU_TO_LE16(x) (x)
/** Performs a conversion on a natively encoded 32-bit piece of data to ensure that it
* is in Little Endian format regardless of the currently selected CPU architecture.
*
* On little endian architectures, this macro does nothing.
*
* \note This macro is designed for compile-time conversion of data - for run-time endianness
* conversion, use \ref cpu_to_le32 instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define CPU_TO_LE32(x) (x)
/** Performs a conversion on a natively encoded 16-bit piece of data to ensure that it
* is in Big Endian format regardless of the currently selected CPU architecture.
*
* On big endian architectures, this macro does nothing.
*
* \note This macro is designed for compile-time conversion of data - for run-time endianness
* conversion, use \ref cpu_to_be16 instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define CPU_TO_BE16(x) SWAPENDIAN_16(x)
/** Performs a conversion on a natively encoded 32-bit piece of data to ensure that it
* is in Big Endian format regardless of the currently selected CPU architecture.
*
* On big endian architectures, this macro does nothing.
*
* \note This macro is designed for compile-time conversion of data - for run-time endianness
* conversion, use \ref cpu_to_be32 instead.
*
* \ingroup Group_EndianConversion
*
* \param[in] x Data to perform the endianness conversion on.
*
* \return Endian corrected version of the input value.
*/
#define CPU_TO_BE32(x) SWAPENDIAN_32(x)
//! @}
#endif
/* Inline Functions: */
/** Function to reverse the byte ordering of the individual bytes in a 16 bit value.
*
* \ingroup Group_ByteSwapping
*
* \param[in] Word Word of data whose bytes are to be swapped.
*
* \return Input data with the individual bytes reversed.
*/
static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST ATTR_ALWAYS_INLINE;
static inline uint16_t SwapEndian_16(const uint16_t Word)
{
if (GCC_IS_COMPILE_CONST(Word))
return SWAPENDIAN_16(Word);
uint8_t Temp;
union
{
uint16_t Word;
uint8_t Bytes[2];
} Data;
Data.Word = Word;
Temp = Data.Bytes[0];
Data.Bytes[0] = Data.Bytes[1];
Data.Bytes[1] = Temp;
return Data.Word;
}
/** Function to reverse the byte ordering of the individual bytes in a 32 bit value.
*
* \ingroup Group_ByteSwapping
*
* \param[in] DWord Double word of data whose bytes are to be swapped.
*
* \return Input data with the individual bytes reversed.
*/
static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST ATTR_ALWAYS_INLINE;
static inline uint32_t SwapEndian_32(const uint32_t DWord)
{
if (GCC_IS_COMPILE_CONST(DWord))
return SWAPENDIAN_32(DWord);
uint8_t Temp;
union
{
uint32_t DWord;
uint8_t Bytes[4];
} Data;
Data.DWord = DWord;
Temp = Data.Bytes[0];
Data.Bytes[0] = Data.Bytes[3];
Data.Bytes[3] = Temp;
Temp = Data.Bytes[1];
Data.Bytes[1] = Data.Bytes[2];
Data.Bytes[2] = Temp;
return Data.DWord;
}
/** Function to reverse the byte ordering of the individual bytes in a n byte value.
*
* \ingroup Group_ByteSwapping
*
* \param[in,out] Data Pointer to a number containing an even number of bytes to be reversed.
* \param[in] Length Length of the data in bytes.
*
* \return Input data with the individual bytes reversed.
*/
static inline void SwapEndian_n(void* const Data,
uint8_t Length) ATTR_NON_NULL_PTR_ARG(1);
static inline void SwapEndian_n(void* const Data,
uint8_t Length)
{
uint8_t* CurrDataPos = (uint8_t*)Data;
while (Length > 1)
{
uint8_t Temp = *CurrDataPos;
*CurrDataPos = *(CurrDataPos + Length - 1);
*(CurrDataPos + Length - 1) = Temp;
CurrDataPos++;
Length -= 2;
}
}
/* Disable C linkage for C++ Compilers: */
#if defined(__cplusplus)
}
#endif
#endif
/** @} */
|
