David Lenfesty
0bff1ffcac
Imported code from larger repo for code. Has some stuff I didn't want here.
111 lines
2.4 KiB
C
111 lines
2.4 KiB
C
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/*
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* Copyright (c) 2006-2012 by Roland Riegel <feedback@roland-riegel.de>
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*
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* This file is free software; you can redistribute it and/or modify
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* it under the terms of either the GNU General Public License version 2
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* or the GNU Lesser General Public License version 2.1, both as
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* published by the Free Software Foundation.
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*/
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#include "byteordering.h"
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/**
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* \addtogroup byteordering
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*
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* Architecture-dependent handling of byte-ordering.
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*
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* @{
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*/
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/**
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* \file
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* Byte-order handling implementation (license: GPLv2 or LGPLv2.1)
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*
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* \author Roland Riegel
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*/
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#if DOXYGEN || SWAP_NEEDED
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/**
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* \internal
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* Swaps the bytes of a 16-bit integer.
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*
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* \param[in] i A 16-bit integer which to swap.
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* \returns The swapped 16-bit integer.
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*/
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uint16_t swap16(uint16_t i)
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{
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return SWAP16(i);
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}
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/**
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* \internal
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* Swaps the bytes of a 32-bit integer.
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*
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* \param[in] i A 32-bit integer which to swap.
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* \returns The swapped 32-bit integer.
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*/
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uint32_t swap32(uint32_t i)
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{
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return SWAP32(i);
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}
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#endif
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/**
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* Reads a 16-bit integer from memory in little-endian byte order.
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*
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* \param[in] p Pointer from where to read the integer.
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* \returns The 16-bit integer read from memory.
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*/
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uint16_t read16(const uint8_t* p)
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{
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return (((uint16_t) p[1]) << 8) |
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(((uint16_t) p[0]) << 0);
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}
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/**
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* Reads a 32-bit integer from memory in little-endian byte order.
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*
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* \param[in] p Pointer from where to read the integer.
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* \returns The 32-bit integer read from memory.
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*/
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uint32_t read32(const uint8_t* p)
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{
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return (((uint32_t) p[3]) << 24) |
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(((uint32_t) p[2]) << 16) |
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(((uint32_t) p[1]) << 8) |
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(((uint32_t) p[0]) << 0);
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}
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/**
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* Writes a 16-bit integer into memory in little-endian byte order.
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*
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* \param[in] p Pointer where to write the integer to.
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* \param[in] i The 16-bit integer to write.
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*/
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void write16(uint8_t* p, uint16_t i)
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{
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p[1] = (uint8_t) ((i & 0xff00) >> 8);
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p[0] = (uint8_t) ((i & 0x00ff) >> 0);
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}
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/**
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* Writes a 32-bit integer into memory in little-endian byte order.
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*
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* \param[in] p Pointer where to write the integer to.
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* \param[in] i The 32-bit integer to write.
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*/
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void write32(uint8_t* p, uint32_t i)
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{
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p[3] = (uint8_t) ((i & 0xff000000) >> 24);
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p[2] = (uint8_t) ((i & 0x00ff0000) >> 16);
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p[1] = (uint8_t) ((i & 0x0000ff00) >> 8);
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p[0] = (uint8_t) ((i & 0x000000ff) >> 0);
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}
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/**
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* @}
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*/
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