incubator-nuttx/include/endian.h

137 lines
4.4 KiB
C

/****************************************************************************
* include/endian.h
*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership. The
* ASF licenses this file to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the
* License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
****************************************************************************/
#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 */