MdePkg/Library/BaseMemoryLibOptDxe/Arm/ScanMemGeneric.c

   1 /** @file
   2   Architecture Independent Base Memory Library Implementation.
   3
   4   The following BaseMemoryLib instances contain the same copy of this file:
   5     BaseMemoryLib
   6     PeiMemoryLib
   7     UefiMemoryLib
   8
   9   Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
  10   SPDX-License-Identifier: BSD-2-Clause-Patent
  11
  12 **/
  13
  14 #include "../MemLibInternals.h"
  15
  16 /**
  17   Scans a target buffer for a 16-bit value, and returns a pointer to the
  18   matching 16-bit value in the target buffer.
  19
  20   @param  Buffer  The pointer to the target buffer to scan.
  21   @param  Length  The count of 16-bit value to scan. Must be non-zero.
  22   @param  Value   The value to search for in the target buffer.
  23
  24   @return The pointer to the first occurrence, or NULL if not found.
  25
  26 **/
  27 CONST VOID *
  28 EFIAPI
  29 InternalMemScanMem16 (
  30   IN      CONST VOID                *Buffer,
  31   IN      UINTN                     Length,
  32   IN      UINT16                    Value
  33   )
  34 {
  35   CONST UINT16                      *Pointer;
  36
  37   Pointer = (CONST UINT16*)Buffer;
  38   do {
  39     if (*Pointer == Value) {
  40       return Pointer;
  41     }
  42     ++Pointer;
  43   } while (--Length != 0);
  44   return NULL;
  45 }
  46
  47 /**
  48   Scans a target buffer for a 32-bit value, and returns a pointer to the
  49   matching 32-bit value in the target buffer.
  50
  51   @param  Buffer  The pointer to the target buffer to scan.
  52   @param  Length  The count of 32-bit value to scan. Must be non-zero.
  53   @param  Value   The value to search for in the target buffer.
  54
  55   @return The pointer to the first occurrence, or NULL if not found.
  56
  57 **/
  58 CONST VOID *
  59 EFIAPI
  60 InternalMemScanMem32 (
  61   IN      CONST VOID                *Buffer,
  62   IN      UINTN                     Length,
  63   IN      UINT32                    Value
  64   )
  65 {
  66   CONST UINT32                      *Pointer;
  67
  68   Pointer = (CONST UINT32*)Buffer;
  69   do {
  70     if (*Pointer == Value) {
  71       return Pointer;
  72     }
  73     ++Pointer;
  74   } while (--Length != 0);
  75   return NULL;
  76 }
  77
  78 /**
  79   Scans a target buffer for a 64-bit value, and returns a pointer to the
  80   matching 64-bit value in the target buffer.
  81
  82   @param  Buffer  The pointer to the target buffer to scan.
  83   @param  Length  The count of 64-bit value to scan. Must be non-zero.
  84   @param  Value   The value to search for in the target buffer.
  85
  86   @return The pointer to the first occurrence, or NULL if not found.
  87
  88 **/
  89 CONST VOID *
  90 EFIAPI
  91 InternalMemScanMem64 (
  92   IN      CONST VOID                *Buffer,
  93   IN      UINTN                     Length,
  94   IN      UINT64                    Value
  95   )
  96 {
  97   CONST UINT64                      *Pointer;
  98
  99   Pointer = (CONST UINT64*)Buffer;
 100   do {
 101     if (*Pointer == Value) {
 102       return Pointer;
 103     }
 104     ++Pointer;
 105   } while (--Length != 0);
 106   return NULL;
 107 }
 108
 109 /**
 110   Checks whether the contents of a buffer are all zeros.
 111
 112   @param  Buffer  The pointer to the buffer to be checked.
 113   @param  Length  The size of the buffer (in bytes) to be checked.
 114
 115   @retval TRUE    Contents of the buffer are all zeros.
 116   @retval FALSE   Contents of the buffer are not all zeros.
 117
 118 **/
 119 BOOLEAN
 120 EFIAPI
 121 InternalMemIsZeroBuffer (
 122   IN CONST VOID  *Buffer,
 123   IN UINTN       Length
 124   )
 125 {
 126   CONST UINT8 *BufferData;
 127   UINTN       Index;
 128
 129   BufferData = Buffer;
 130   for (Index = 0; Index < Length; Index++) {
 131     if (BufferData[Index] != 0) {
 132       return FALSE;
 133     }
 134   }
 135   return TRUE;
 136 }