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      1 /** @file
      2   ScanMem32() implementation.
      3 
      4   The following BaseMemoryLib instances contain the same copy of this file:
      5     BaseMemoryLib
      6     BaseMemoryLibMmx
      7     BaseMemoryLibSse2
      8     BaseMemoryLibRepStr
      9     BaseMemoryLibOptDxe
     10     BaseMemoryLibOptPei
     11     PeiMemoryLib
     12     UefiMemoryLib
     13 
     14   Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
     15   This program and the accompanying materials
     16   are licensed and made available under the terms and conditions of the BSD License
     17   which accompanies this distribution.  The full text of the license may be found at
     18   http://opensource.org/licenses/bsd-license.php.
     19 
     20   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
     21   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
     22 
     23 **/
     24 
     25 #include "MemLibInternals.h"
     26 
     27 /**
     28   Scans a target buffer for a 32-bit value, and returns a pointer to the matching 32-bit value
     29   in the target buffer.
     30 
     31   This function searches the target buffer specified by Buffer and Length from the lowest
     32   address to the highest address for a 32-bit value that matches Value.  If a match is found,
     33   then a pointer to the matching byte in the target buffer is returned.  If no match is found,
     34   then NULL is returned.  If Length is 0, then NULL is returned.
     35 
     36   If Length > 0 and Buffer is NULL, then ASSERT().
     37   If Buffer is not aligned on a 32-bit boundary, then ASSERT().
     38   If Length is not aligned on a 32-bit boundary, then ASSERT().
     39   If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
     40 
     41   @param  Buffer      The pointer to the target buffer to scan.
     42   @param  Length      The number of bytes in Buffer to scan.
     43   @param  Value       The value to search for in the target buffer.
     44 
     45   @return A pointer to the matching byte in the target buffer or NULL otherwise.
     46 
     47 **/
     48 VOID *
     49 EFIAPI
     50 ScanMem32 (
     51   IN CONST VOID  *Buffer,
     52   IN UINTN       Length,
     53   IN UINT32      Value
     54   )
     55 {
     56   if (Length == 0) {
     57     return NULL;
     58   }
     59 
     60   ASSERT (Buffer != NULL);
     61   ASSERT (((UINTN)Buffer & (sizeof (Value) - 1)) == 0);
     62   ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)Buffer));
     63   ASSERT ((Length & (sizeof (Value) - 1)) == 0);
     64 
     65   return (VOID*)InternalMemScanMem32 (Buffer, Length / sizeof (Value), Value);
     66 }
     67