1 files changed, 60 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseMemoryLib/CopyMem.c b/MdePkg/Library/BaseMemoryLib/CopyMem.c
new file mode 100644
index 0000000000..f2106acb18
--- /dev/null
+++ b/MdePkg/Library/BaseMemoryLib/CopyMem.c
@@ -0,0 +1,60 @@
+/** @file
+  Implementation of the EfiCopyMem routine. This function is broken
+  out into its own source file so that it can be excluded from a
+  build for a particular platform easily if an optimized version
+  is desired.
+
+  Copyright (c) 2006, Intel Corporation<BR>
+  All rights reserved. This program and the accompanying materials
+  are licensed and made available under the terms and conditions of the BSD License
+  which accompanies this distribution.  The full text of the license may be found at
+  http://opensource.org/licenses/bsd-license.php
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+  Module Name:  EfiCopyMem.c
+
+**/
+
+/**
+  Copy Length bytes from Source to Destination.
+
+  @param  Destination Target of copy
+  @param  Source Place to copy from
+  @param  Length Number of bytes to copy
+
+  @return Destination
+
+**/
+VOID *
+EFIAPI
+InternalMemCopyMem (
+  OUT     VOID                      *Destination,
+  IN      CONST VOID                *Source,
+  IN      UINTN                     Length
+  )
+{
+  //
+  // Declare the local variables that actually move the data elements as
+  // volatile to prevent the optimizer from replacing this function with
+  // the intrinsic memcpy()
+  //
+  volatile UINT8                    *Destination8;
+  CONST UINT8                       *Source8;
+
+  if (Source > Destination) {
+    Destination8 = (UINT8*)Destination;
+    Source8 = (CONST UINT8*)Source;
+    while (Length-- != 0) {
+      *(Destination8++) = *(Source8++);
+    }
+  } else if (Source < Destination) {
+    Destination8 = (UINT8*)Destination + Length;
+    Source8 = (CONST UINT8*)Source + Length;
+    while (Length-- != 0) {
+      *(--Destination8) = *(--Source8);
+    }
+  }
+  return Destination;
+}