blob: f890b0301ceca11b5c78698373170c8dfd9404e0 [file] [log] [blame]
/****************************************************************************
* include/endian.h
*
* Copyright (C) 2018 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
* OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
****************************************************************************/
#ifndef __INCLUDE_ENDIAN_H
#define __INCLUDE_ENDIAN_H
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <nuttx/compiler.h>
#include <stdint.h>
/****************************************************************************
* Preprocessor definitions
****************************************************************************/
/* The endian.h header must define at least the following macros for use in
* determining host byte order for integer types:
*
* BYTE_ORDER This macro will have a value equal to one of the *_ENDIAN
* macros in this header.
* LITTLE_ENDIAN If BYTE_ORDER == LITTLE_ENDIAN, the host byte order is
* from least significant to most significant.
* BIG_ENDIAN If BYTE_ORDER == BIG_ENDIAN, the host byte order is from
* most significant to least significant.
*/
#define LITTLE_ENDIAN 1234
#define BIG_ENDIAN 4321
/* Common byte swapping macros */
#define __SWAP_UINT16_ISMACRO 1
#undef __SWAP_UINT32_ISMACRO
#ifdef __SWAP_UINT16_ISMACRO
# define __swap_uint16(n) \
(uint16_t)(((((uint16_t)(n)) & 0x00ff) << 8) | \
((((uint16_t)(n)) >> 8) & 0x00ff))
#endif
#ifdef __SWAP_UINT32_ISMACRO
# define __swap_uint32(n) \
(uint32_t)(((((uint32_t)(n)) & 0x000000ffUL) << 24) | \
((((uint32_t)(n)) & 0x0000ff00UL) << 8) | \
((((uint32_t)(n)) & 0x00ff0000UL) >> 8) | \
((((uint32_t)(n)) & 0xff000000UL) >> 24))
#endif
/* Endian-specific definitions */
#ifdef CONFIG_ENDIAN_BIG
/* Big-endian byte order */
# define BYTE_ORDER BIG_ENDIAN
/* Big-endian byte order macros */
# define htobe16(n) (n)
# define htole16(n) __swap_uint16((uint16_t)n)
# define be16toh(n) (n)
# define le16toh(n) __swap_uint16((uint16_t)n)
# define htobe32(n) (n)
# define htole32(n) __swap_uint32((uint32_t)n)
# define be32toh(n) (n)
# define le32toh(n) __swap_uint32(n)
# ifdef CONFIG_HAVE_LONG_LONG
# define htobe64(n) (n)
# define htole64(n) __swap_uint64((uint64_t)n)
# define be64toh(n) (n)
# define le64toh(n) __swap_uint64((uint64_t)n)
# endif
#else
/* Little-endian byte order */
# define BYTE_ORDER LITTLE_ENDIAN
/* Little-endian byte order macros */
# define htobe16(n) __swap_uint16((uint16_t)n)
# define htole16(n) (n)
# define be16toh(n) __swap_uint16((uint16_t)n)
# define le16toh(n) (n)
# define htobe32(n) __swap_uint32((uint32_t)n)
# define htole32(n) (n)
# define be32toh(n) __swap_uint32((uint32_t)n)
# define le32toh(n) (n)
# ifdef CONFIG_HAVE_LONG_LONG
# define htobe64(n) __swap_uint64((uint64_t)n)
# define htole64(n) (n)
# define be64toh(n) __swap_uint64((uint64_t)n)
# define le64toh(n) (n)
# endif
#endif
/****************************************************************************
* Public Function Prototypes
****************************************************************************/
#ifndef __SWAP_UINT16_ISMACRO
uint16_t __swap_uint16(uint16_t n);
#endif
#ifndef __SWAP_UINT32_ISMACRO
uint32_t __swap_uint32(uint32_t n);
#endif
#if CONFIG_HAVE_LONG_LONG
uint64_t __swap_uint64(uint64_t n);
#endif
#endif /* __INCLUDE_ENDIAN_H */