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/* Copyright (c) 1996-2004, Adaptec Corporation
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* - 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.
* - Neither the name of the Adaptec Corporation 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.
*/
//File - SWAP_EM.C
//***************************************************************************
//
//Description:
//
// This file contains the definitions for the functions to reverse
//the byte ordering of 2 and 4 byte variables.
//
//Author: Bob Roycroft
//Date: 06/20/94
//
//Editors:
//
//Remarks:
//
//
//***************************************************************************
//Include Files -------------------------------------------------------------
#include "osd_util.h"
//Function - osdSwap4() - start
//===========================================================================
//
//Description:
//
// This function reverses the byte ordering of a four byte variable.
//
//Parameters:
//
// inLong_P = Pointer to the 4 byte variable to be byte reversed.
//
//Return Value:
//
// The byte reversed variable.
// Note that the input variable is also reversed.
//
//Global Variables Affected:
//
//Remarks: (Side effects, Assumptions, Warnings...)
//
//
//---------------------------------------------------------------------------
#ifndef _DPT_NETWARE
uLONG osdSwap4(DPT_UNALIGNED uLONG * dwdp)
{
#ifndef _DPT_BIG_ENDIAN
uSHORT wd0, wd1;
wd0 = (uSHORT) *dwdp;
wd1 = (uSHORT) (*dwdp>>16);
wd0 = ((uSHORT) ((wd0>>8) | (wd0<<8)));
wd1 = ((uSHORT) ((wd1>>8) | (wd1<<8)));
return (* dwdp = (((uLONG)wd0<<16) | wd1));
#else
return *dwdp;
#endif
}
#endif
//Function - osdSwap2() - start
//===========================================================================
//
//Description:
//
// This function swaps the MSB & LSB of a two byte variable.
//
//Parameters:
//
// inShort_P = Pointer to the 2 byte variable to be byte reversed.
//
//Return Value:
//
// The byte reversed variable
// Note that the input variable is also reversed.
//
//Global Variables Affected:
//
//Remarks: (Side effects, Assumptions, Warnings...)
//
//
//---------------------------------------------------------------------------
uSHORT osdSwap2(DPT_UNALIGNED uSHORT * wdp)
{
#ifndef _DPT_BIG_ENDIAN
return (* wdp = ((uSHORT) (((*wdp>>8) | (*wdp<<8)))));
#else
return *wdp;
#endif
}
//Function - osdSwap3() - start
//===========================================================================
//
//Description:
//
// This function reverses the byte ordering of a three byte variable.
//
//Parameters:
//
// inLong_P = Pointer to the 4 byte variable to be byte reversed.
//
//Return Value:
//
// The byte reversed variable.
// Note that the input variable is also reversed.
//
//Global Variables Affected:
//
//Remarks: (Side effects, Assumptions, Warnings...)
//
//
//---------------------------------------------------------------------------
uLONG osdSwap3(DPT_UNALIGNED uLONG * dwdp)
{
#ifndef _DPT_BIG_ENDIAN
uSHORT wd0, wd1;
wd0 = (uSHORT) *dwdp;
wd1 = (uSHORT) (*dwdp>>16);
wd0 = ((uSHORT) ((wd0>>8) | (wd0<<8)));
wd1 = ((uSHORT) ((wd1>>8) | (wd1<<8)));
return (* dwdp = ((((uLONG)wd0<<16) | wd1) >> 8));
#else
return *dwdp;
#endif
}
/*Function - trueSwap2 - start */
/*===========================================================================*/
/* */
/*Description: */
/* */
/* This function ALWAYS swaps the MSB & LSB of a two byte variable. */
/* */
/*Parameters: */
/* */
/*Return Value: */
/* */
/*Global Variables Affected: */
/* */
/*Remarks: (Side effects, Assumptions, Warnings...) */
/* */
/* */
/*---------------------------------------------------------------------------*/
uSHORT trueSwap2(uSHORT *inShort)
{
uSHORT i;
i = (uSHORT) (*inShort & 0x0ff);
*inShort >>= 8;
*inShort |= (i << 8);
return(*inShort);
}
/* trueSwap2() - end */
/*Function - trueSwap4 - start */
/*===========================================================================*/
/* */
/*Description: */
/* */
/* This function ALWAYS reverses the byte ordering of a four byte variable. */
/* */
/*Parameters: */
/* */
/*Return Value: */
/* */
/*Global Variables Affected: */
/* */
/*Remarks: (Side effects, Assumptions, Warnings...) */
/* */
/* */
/*---------------------------------------------------------------------------*/
uLONG trueSwap4(uLONG *inLong)
{
char src[4], *dst;
int i;
*(uLONG *)src = *inLong;
dst = (char *)inLong;
for(i = 0; i < 4; ++i)
{
dst[i] = src[3 - i];
}
return(*inLong);
}
/* trueSwap4() - end */
//Function - netSwap4() - start
//===========================================================================
//
//Description:
//
// This function ensures that the input four byte variable is returned
// in DPT network order (little-endian). On big-endian machines this
// function will swap the four byte variable. On little-endian machines
// this function will return the input value.
//
//Parameters:
//
// val = 4 byte variable to be byte reversed.
//
//Return Value:
//
// The variable in network order.
//
//Global Variables Affected:
//
//Remarks: (Side effects, Assumptions, Warnings...)
//
//---------------------------------------------------------------------------
uLONG netSwap4(uLONG val)
{
#if defined (_DPT_BIG_ENDIAN)
// we need to swap the value and return it
uSHORT wd0, wd1;
wd0 = (uSHORT) val;
wd1 = (uSHORT) (val >> 16);
wd0 = (wd0 >> 8) | (wd0 << 8);
wd1 = (wd1 >> 8) | (wd1 << 8);
return (((uLONG)wd0 << 16) | wd1);
#else
// just return the value for little-endian machines
return val;
#endif // big_endian
}
//netSwap4() - end
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