ArmPkg/Library/BaseMemoryLibVstm/CopyMemWrapper.c

   1 /** @file
   2   CopyMem() implementation.
   3
   4   The following BaseMemoryLib instances contain the same copy of this file:
   5
   6     BaseMemoryLib
   7     BaseMemoryLibMmx
   8     BaseMemoryLibSse2
   9     BaseMemoryLibRepStr
  10     BaseMemoryLibOptDxe
  11     BaseMemoryLibOptPei
  12     PeiMemoryLib
  13     UefiMemoryLib
  14
  15   Copyright (c) 2006 - 2009, Intel Corporation<BR>
  16   All rights reserved. This program and the accompanying materials
  17   are licensed and made available under the terms and conditions of the BSD License
  18   which accompanies this distribution.  The full text of the license may be found at
  19   http://opensource.org/licenses/bsd-license.php
  20
  21   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  22   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  23
  24 **/
  25
  26 #include "MemLibInternals.h"
  27
  28 /**
  29   Copies a source buffer to a destination buffer, and returns the destination buffer.
  30
  31   This function copies Length bytes from SourceBuffer to DestinationBuffer, and returns
  32   DestinationBuffer.  The implementation must be reentrant, and it must handle the case
  33   where SourceBuffer overlaps DestinationBuffer.
  34
  35   If Length is greater than (MAX_ADDRESS - DestinationBuffer + 1), then ASSERT().
  36   If Length is greater than (MAX_ADDRESS - SourceBuffer + 1), then ASSERT().
  37
  38   @param  DestinationBuffer   Pointer to the destination buffer of the memory copy.
  39   @param  SourceBuffer        Pointer to the source buffer of the memory copy.
  40   @param  Length              Number of bytes to copy from SourceBuffer to DestinationBuffer.
  41
  42   @return DestinationBuffer.
  43
  44 **/
  45 VOID *
  46 EFIAPI
  47 CopyMem (
  48   OUT VOID       *DestinationBuffer,
  49   IN CONST VOID  *SourceBuffer,
  50   IN UINTN       Length
  51   )
  52 {
  53   if (Length == 0) {
  54     return DestinationBuffer;
  55   }
  56   ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)DestinationBuffer));
  57   ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)SourceBuffer));
  58
  59   if (DestinationBuffer == SourceBuffer) {
  60     return DestinationBuffer;
  61   }
  62   return InternalMemCopyMem (DestinationBuffer, SourceBuffer, Length);
  63 }