X-Git-Url: https://git.proxmox.com/?a=blobdiff_plain;f=MdePkg%2FLibrary%2FBaseMemoryLib%2FScanMem32Wrapper.c;h=60d5eff683ade042b5cdd2123b624e355fccf27e;hb=56385d49874f4b7cee6c9a0652c6b7c10aff0e2f;hp=67eb84d8ef4486fc8b8fbb4bf7e44c14170422de;hpb=24de7645e857287d096b058f7a64fb7f618c0194;p=mirror_edk2.git

diff --git a/MdePkg/Library/BaseMemoryLib/ScanMem32Wrapper.c b/MdePkg/Library/BaseMemoryLib/ScanMem32Wrapper.c
index 67eb84d8ef..60d5eff683 100644
--- a/MdePkg/Library/BaseMemoryLib/ScanMem32Wrapper.c
+++ b/MdePkg/Library/BaseMemoryLib/ScanMem32Wrapper.c
@@ -1,7 +1,17 @@
 /** @file
   ScanMem32() implementation.
 
-  Copyright (c) 2006, Intel Corporation<BR>
+  The following BaseMemoryLib instances contain the same copy of this file:
+    BaseMemoryLib
+    BaseMemoryLibMmx
+    BaseMemoryLibSse2
+    BaseMemoryLibRepStr
+    BaseMemoryLibOptDxe
+    BaseMemoryLibOptPei
+    PeiMemoryLib
+    UefiMemoryLib
+
+  Copyright (c) 2006 - 2009, 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
@@ -10,57 +20,47 @@
   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:  ScanMem32Wrapper.c
-
-  The following BaseMemoryLib instances share the same version of this file:
-
-    BaseMemoryLib
-    BaseMemoryLibMmx
-    BaseMemoryLibSse2
-    BaseMemoryLibRepStr
-    PeiMemoryLib
-    UefiMemoryLib
-
 **/
 
 #include "MemLibInternals.h"
 
 /**
-  Scans a target buffer for a 32-bit value, and returns a pointer to the
-  matching 32-bit value in the target buffer.
-
-  This function searches target the buffer specified by Buffer and Length from
-  the lowest address to the highest address at 32-bit increments for a 32-bit
-  value that matches Value. If a match is found, then a pointer to the matching
-  value in the target buffer is returned. If no match is found, then NULL is
-  returned. If Length is 0, then NULL is returned.
+  Scans a target buffer for a 32-bit value, and returns a pointer to the matching 32-bit value
+  in the target buffer.
 
-  If Buffer is NULL, then ASSERT().
+  This function searches the target buffer specified by Buffer and Length from the lowest
+  address to the highest address for a 32-bit value that matches Value.  If a match is found,
+  then a pointer to the matching byte in the target buffer is returned.  If no match is found,
+  then NULL is returned.  If Length is 0, then NULL is returned.
+  
+  If Length > 0 and Buffer is NULL, then ASSERT().
   If Buffer is not aligned on a 32-bit boundary, then ASSERT().
+  If Length is not aligned on a 32-bit boundary, then ASSERT().
   If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
 
-  @param  Buffer  Pointer to the target buffer to scan.
-  @param  Length  Number of bytes in Buffer to scan.
-  @param  Value   Value to search for in the target buffer.
+  @param  Buffer      Pointer to the target buffer to scan.
+  @param  Length      Number of bytes in Buffer to scan.
+  @param  Value       Value to search for in the target buffer.
 
-  @return Pointer to the first occurrence or NULL if not found.
-  @retval NULL  if Length == 0 or Value was not found.
+  @return A pointer to the matching byte in the target buffer or NULL otherwise.
 
 **/
 VOID *
 EFIAPI
 ScanMem32 (
-  IN      CONST VOID                *Buffer,
-  IN      UINTN                     Length,
-  IN      UINT32                    Value
+  IN CONST VOID  *Buffer,
+  IN UINTN       Length,
+  IN UINT32      Value
   )
 {
+  if (Length == 0) {
+    return NULL;
+  }
+
   ASSERT (Buffer != NULL);
   ASSERT (((UINTN)Buffer & (sizeof (Value) - 1)) == 0);
-  ASSERT (Length <= MAX_ADDRESS + (UINTN)Buffer + 1);
+  ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)Buffer));
+  ASSERT ((Length & (sizeof (Value) - 1)) == 0);
 
-  if ((Length /= sizeof (Value)) == 0) {
-    return NULL;
-  }
-  return (VOID*)InternalMemScanMem32 (Buffer, Length, Value);
+  return (VOID*)InternalMemScanMem32 (Buffer, Length / sizeof (Value), Value);
 }