1 /** @file
2   ScanMem8() and ScanMemN() 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 - 2018, Intel Corporation. All rights reserved.<BR>
16   SPDX-License-Identifier: BSD-2-Clause-Patent
17 
18 **/
19 
20 #include "MemLibInternals.h"
21 
22 /**
23   Scans a target buffer for an 8-bit value, and returns a pointer to the matching 8-bit value
24   in the target buffer.
25 
26   This function searches the target buffer specified by Buffer and Length from the lowest
27   address to the highest address for an 8-bit value that matches Value.  If a match is found,
28   then a pointer to the matching byte in the target buffer is returned.  If no match is found,
29   then NULL is returned.  If Length is 0, then NULL is returned.
30 
31   If Length > 0 and Buffer is NULL, then ASSERT().
32   If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
33 
34   @param  Buffer      The pointer to the target buffer to scan.
35   @param  Length      The number of bytes in Buffer to scan.
36   @param  Value       The value to search for in the target buffer.
37 
38   @return A pointer to the matching byte in the target buffer, or NULL otherwise.
39 
40 **/
41 VOID *
42 EFIAPI
43 ScanMem8 (
44   IN CONST VOID  *Buffer,
ScanMem16(IN CONST VOID * Buffer,IN UINTN Length,IN UINT16 Value)45   IN UINTN       Length,
46   IN UINT8       Value
47   )
48 {
49   if (Length == 0) {
50     return NULL;
51   }
52   ASSERT (Buffer != NULL);
53   ASSERT ((Length - 1) <= (MAX_ADDRESS - (UINTN)Buffer));
54 
55   return (VOID*)InternalMemScanMem8 (Buffer, Length, Value);
56 }
57 
58 /**
59   Scans a target buffer for a UINTN sized value, and returns a pointer to the matching
60   UINTN sized value in the target buffer.
61 
62   This function searches the target buffer specified by Buffer and Length from the lowest
63   address to the highest address for a UINTN sized value that matches Value.  If a match is found,
64   then a pointer to the matching byte in the target buffer is returned.  If no match is found,
65   then NULL is returned.  If Length is 0, then NULL is returned.
66 
67   If Length > 0 and Buffer is NULL, then ASSERT().
68   If Buffer is not aligned on a UINTN boundary, then ASSERT().
69   If Length is not aligned on a UINTN boundary, then ASSERT().
70   If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().
71 
72   @param  Buffer      The pointer to the target buffer to scan.
73   @param  Length      The number of bytes in Buffer to scan.
74   @param  Value       The value to search for in the target buffer.
75 
76   @return A pointer to the matching byte in the target buffer, or NULL otherwise.
77 
78 **/
79 VOID *
80 EFIAPI
81 ScanMemN (
82   IN CONST VOID  *Buffer,
83   IN UINTN       Length,
84   IN UINTN       Value
85   )
86 {
87   if (sizeof (UINTN) == sizeof (UINT64)) {
88     return ScanMem64 (Buffer, Length, (UINT64)Value);
89   } else {
90     return ScanMem32 (Buffer, Length, (UINT32)Value);
91   }
92 }
93 
94