/* * @brief Endianness declaration * * @note * Copyright(C) NXP Semiconductors, 2012 * Copyright(C) Dean Camera, 2011, 2012 * All rights reserved. * * @par * Software that is described herein is for illustrative purposes only * which provides customers with programming information regarding the * LPC products. This software is supplied "AS IS" without any warranties of * any kind, and NXP Semiconductors and its licensor disclaim any and * all warranties, express or implied, including all implied warranties of * merchantability, fitness for a particular purpose and non-infringement of * intellectual property rights. NXP Semiconductors assumes no responsibility * or liability for the use of the software, conveys no license or rights under any * patent, copyright, mask work right, or any other intellectual property rights in * or to any products. NXP Semiconductors reserves the right to make changes * in the software without notification. NXP Semiconductors also makes no * representation or warranty that such application will be suitable for the * specified use without further testing or modification. * * @par * Permission to use, copy, modify, and distribute this software and its * documentation is hereby granted, under NXP Semiconductors' and its * licensor's relevant copyrights in the software, without fee, provided that it * is used in conjunction with NXP Semiconductors microcontrollers. This * copyright, permission, and disclaimer notice must appear in all copies of * this code. */ /** @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 __LPCUSBlib_ENDIANNESS_H__ #define __LPCUSBlib_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 LPCUSBlib/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. * * @ingroup Group_ByteSwapping * * @param 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. * * @ingroup Group_ByteSwapping * * @param 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 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 Word Word of data whose bytes are to be swapped. */ static inline uint16_t SwapEndian_16(const uint16_t Word) ATTR_WARN_UNUSED_RESULT ATTR_CONST; 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 DWord Double word of data whose bytes are to be swapped. */ static inline uint32_t SwapEndian_32(const uint32_t DWord) ATTR_WARN_UNUSED_RESULT ATTR_CONST; 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 Length Length of the data in bytes. */ 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 /** @} */