source: bootcd/isolinux/syslinux-6.03/gnu-efi/gnu-efi-3.0/lib/runtime/efirtlib.c

/*++

Copyright (c) 1999  Intel Corporation

Module Name:

    EfiRtLib.h

Abstract:

    EFI Runtime library functions



Revision History

--*/

#include "efi.h"
#include "efilib.h"
#include "efirtlib.h"

#ifndef __GNUC__
#pragma RUNTIME_CODE(RtZeroMem)
#endif
VOID
RUNTIMEFUNCTION
RtZeroMem (
    IN VOID     *Buffer,
    IN UINTN     Size
    )
{
    INT8        *pt;

    pt = Buffer;
    while (Size--) {
        *(pt++) = 0;
    }
}

#ifndef __GNUC__
#pragma RUNTIME_CODE(RtSetMem)
#endif
VOID
RUNTIMEFUNCTION
RtSetMem (
    IN VOID     *Buffer,
    IN UINTN    Size,
    IN UINT8    Value    
    )
{
    INT8        *pt;

    pt = Buffer;
    while (Size--) {
        *(pt++) = Value;
    }
}

#ifndef __GNUC__
#pragma RUNTIME_CODE(RtCopyMem)
#endif
VOID
RUNTIMEFUNCTION
RtCopyMem (
    IN VOID     *Dest,
    IN CONST VOID     *Src,
    IN UINTN    len
    )
{
    CHAR8   *d;
    CONST CHAR8 *s = Src;
    d = Dest;
    while (len--) {
        *(d++) = *(s++);
    }
}

#ifndef __GNUC__
#pragma RUNTIME_CODE(RtCompareMem)
#endif
INTN
RUNTIMEFUNCTION
RtCompareMem (
    IN CONST VOID     *Dest,
    IN CONST VOID     *Src,
    IN UINTN    len
    )
{
    CONST CHAR8    *d = Dest, *s = Src;
    while (len--) {
        if (*d != *s) {
            return *d - *s;
        }

        d += 1;
        s += 1;
    }

    return 0;
}

#ifndef __GNUC__
#pragma RUNTIME_CODE(RtCompareGuid)
#endif
INTN
RUNTIMEFUNCTION
RtCompareGuid (
    IN EFI_GUID     *Guid1,
    IN EFI_GUID     *Guid2
    )
/*++

Routine Description:

    Compares to GUIDs

Arguments:

    Guid1       - guid to compare
    Guid2       - guid to compare

Returns:
    = 0     if Guid1 == Guid2

--*/
{
    INT32       *g1, *g2, r;

    //
    // Compare 32 bits at a time
    //

    g1 = (INT32 *) Guid1;
    g2 = (INT32 *) Guid2;

    r  = g1[0] - g2[0];
    r |= g1[1] - g2[1];
    r |= g1[2] - g2[2];
    r |= g1[3] - g2[3];

    return r;
}