windows-xp/Source/XPSP1/NT/base/ntos/inc/cpyuchr.h

/*++

Copyright (c) 1989  Microsoft Corporation

Module Name:

    cpyuchr.h

Abstract:

    A more central set of definitions for unpacking unaligned
    data (i.e. for unbpacking bios parameter blocks).

Author:

Revision History:

--*/

#ifndef CopyUchar1
//
//  The following types and macros are used to help unpack the packed and
//  misaligned fields found in the Bios parameter block
//

typedef union _UCHAR1 {
    UCHAR  Uchar[1];
    UCHAR  ForceAlignment;
} UCHAR1, *PUCHAR1;

typedef union _UCHAR2 {
    UCHAR  Uchar[2];
    USHORT ForceAlignment;
} UCHAR2, *PUCHAR2;

typedef union _UCHAR4 {
    UCHAR  Uchar[4];
    ULONG  ForceAlignment;
} UCHAR4, *PUCHAR4;

//
//  This macro copies an unaligned src byte to an aligned dst byte
//

#define CopyUchar1(Dst,Src) {                                \
    *((UCHAR1 *)(Dst)) = *((UNALIGNED UCHAR1 *)(Src)); \
    }

//
//  This macro copies an unaligned src word to an aligned dst word
//

#define CopyUchar2(Dst,Src) {                                \
    *((UCHAR2 *)(Dst)) = *((UNALIGNED UCHAR2 *)(Src)); \
    }

//
//  This macro copies an unaligned src longword to an aligned dsr longword
//

#define CopyUchar4(Dst,Src) {                                \
    *((UCHAR4 *)(Dst)) = *((UNALIGNED UCHAR4 *)(Src)); \
    }

#define CopyU4char(Dst,Src) {                                \
    *((UNALIGNED UCHAR4 *)(Dst)) = *((UCHAR4 *)(Src)); \
    }

#endif