MdePkg/Library/BaseMemoryLib/MemLibGeneric.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 - 2010, Intel Corporation. All rights reserved.<BR>
  10   This program and the accompanying materials
  11   are licensed and made available under the terms and conditions of the BSD License
  12   which accompanies this distribution.  The full text of the license may be found at
  13   http://opensource.org/licenses/bsd-license.php.
  14
  15   THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  16   WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  17
  18 **/
  19
  20 #include "MemLibInternals.h"
  21
  22 /**
  23   Fills a target buffer with a 16-bit value, and returns the target buffer.
  24
  25   @param  Buffer  The pointer to the target buffer to fill.
  26   @param  Length  The count of 16-bit value to fill.
  27   @param  Value   The value with which to fill Length bytes of Buffer.
  28
  29   @return Buffer
  30
  31 **/
  32 VOID *
  33 EFIAPI
  34 InternalMemSetMem16 (
  35   OUT     VOID                      *Buffer,
  36   IN      UINTN                     Length,
  37   IN      UINT16                    Value
  38   )
  39 {
  40   do {
  41     ((UINT16*)Buffer)[--Length] = Value;
  42   } while (Length != 0);
  43   return Buffer;
  44 }
  45
  46 /**
  47   Fills a target buffer with a 32-bit value, and returns the target buffer.
  48
  49   @param  Buffer  The pointer to the target buffer to fill.
  50   @param  Length  The count of 32-bit value to fill.
  51   @param  Value   The value with which to fill Length bytes of Buffer.
  52
  53   @return Buffer
  54
  55 **/
  56 VOID *
  57 EFIAPI
  58 InternalMemSetMem32 (
  59   OUT     VOID                      *Buffer,
  60   IN      UINTN                     Length,
  61   IN      UINT32                    Value
  62   )
  63 {
  64   do {
  65     ((UINT32*)Buffer)[--Length] = Value;
  66   } while (Length != 0);
  67   return Buffer;
  68 }
  69
  70 /**
  71   Fills a target buffer with a 64-bit value, and returns the target buffer.
  72
  73   @param  Buffer  The pointer to the target buffer to fill.
  74   @param  Length  The count of 64-bit value to fill.
  75   @param  Value   The value with which to fill Length bytes of Buffer.
  76
  77   @return Buffer
  78
  79 **/
  80 VOID *
  81 EFIAPI
  82 InternalMemSetMem64 (
  83   OUT     VOID                      *Buffer,
  84   IN      UINTN                     Length,
  85   IN      UINT64                    Value
  86   )
  87 {
  88   do {
  89     ((UINT64*)Buffer)[--Length] = Value;
  90   } while (Length != 0);
  91   return Buffer;
  92 }
  93
  94 /**
  95   Set Buffer to 0 for Size bytes.
  96
  97   @param  Buffer Memory to set.
  98   @param  Length The number of bytes to set.
  99
 100   @return Buffer
 101
 102 **/
 103 VOID *
 104 EFIAPI
 105 InternalMemZeroMem (
 106   OUT     VOID                      *Buffer,
 107   IN      UINTN                     Length
 108   )
 109 {
 110   return InternalMemSetMem (Buffer, Length, 0);
 111 }
 112
 113 /**
 114   Compares two memory buffers of a given length.
 115
 116   @param  DestinationBuffer The first memory buffer.
 117   @param  SourceBuffer      The second memory buffer.
 118   @param  Length            Length of DestinationBuffer and SourceBuffer memory
 119                             regions to compare. Must be non-zero.
 120
 121   @return 0                 All Length bytes of the two buffers are identical.
 122   @retval Non-zero          The first mismatched byte in SourceBuffer subtracted from the first
 123                             mismatched byte in DestinationBuffer.
 124
 125 **/
 126 INTN
 127 EFIAPI
 128 InternalMemCompareMem (
 129   IN      CONST VOID                *DestinationBuffer,
 130   IN      CONST VOID                *SourceBuffer,
 131   IN      UINTN                     Length
 132   )
 133 {
 134   while ((--Length != 0) &&
 135          (*(INT8*)DestinationBuffer == *(INT8*)SourceBuffer)) {
 136     DestinationBuffer = (INT8*)DestinationBuffer + 1;
 137     SourceBuffer = (INT8*)SourceBuffer + 1;
 138   }
 139   return (INTN)*(UINT8*)DestinationBuffer - (INTN)*(UINT8*)SourceBuffer;
 140 }
 141
 142 /**
 143   Scans a target buffer for an 8-bit value, and returns a pointer to the
 144   matching 8-bit value in the target buffer.
 145
 146   @param  Buffer  The pointer to the target buffer to scan.
 147   @param  Length  The count of 8-bit value to scan. Must be non-zero.
 148   @param  Value   The value to search for in the target buffer.
 149
 150   @return The pointer to the first occurrence, or NULL if not found.
 151
 152 **/
 153 CONST VOID *
 154 EFIAPI
 155 InternalMemScanMem8 (
 156   IN      CONST VOID                *Buffer,
 157   IN      UINTN                     Length,
 158   IN      UINT8                     Value
 159   )
 160 {
 161   CONST UINT8                       *Pointer;
 162
 163   Pointer = (CONST UINT8*)Buffer;
 164   do {
 165     if (*(Pointer++) == Value) {
 166       return Pointer;
 167     }
 168   } while (--Length != 0);
 169   return NULL;
 170 }
 171
 172 /**
 173   Scans a target buffer for a 16-bit value, and returns a pointer to the
 174   matching 16-bit value in the target buffer.
 175
 176   @param  Buffer  The pointer to the target buffer to scan.
 177   @param  Length  The count of 16-bit value to scan. Must be non-zero.
 178   @param  Value   The value to search for in the target buffer.
 179
 180   @return The pointer to the first occurrence, or NULL if not found.
 181
 182 **/
 183 CONST VOID *
 184 EFIAPI
 185 InternalMemScanMem16 (
 186   IN      CONST VOID                *Buffer,
 187   IN      UINTN                     Length,
 188   IN      UINT16                    Value
 189   )
 190 {
 191   CONST UINT16                      *Pointer;
 192
 193   Pointer = (CONST UINT16*)Buffer;
 194   do {
 195     if (*(Pointer++) == Value) {
 196       return Pointer;
 197     }
 198   } while (--Length != 0);
 199   return NULL;
 200 }
 201
 202 /**
 203   Scans a target buffer for a 32-bit value, and returns a pointer to the
 204   matching 32-bit value in the target buffer.
 205
 206   @param  Buffer  The pointer to the target buffer to scan.
 207   @param  Length  The count of 32-bit value to scan. Must be non-zero.
 208   @param  Value   The value to search for in the target buffer.
 209
 210   @return The pointer to the first occurrence, or NULL if not found.
 211
 212 **/
 213 CONST VOID *
 214 EFIAPI
 215 InternalMemScanMem32 (
 216   IN      CONST VOID                *Buffer,
 217   IN      UINTN                     Length,
 218   IN      UINT32                    Value
 219   )
 220 {
 221   CONST UINT32                      *Pointer;
 222
 223   Pointer = (CONST UINT32*)Buffer;
 224   do {
 225     if (*(Pointer++) == Value) {
 226       return Pointer;
 227     }
 228   } while (--Length != 0);
 229   return NULL;
 230 }
 231
 232 /**
 233   Scans a target buffer for a 64-bit value, and returns a pointer to the
 234   matching 64-bit value in the target buffer.
 235
 236   @param  Buffer  The pointer to the target buffer to scan.
 237   @param  Length  The count of 64-bit value to scan. Must be non-zero.
 238   @param  Value   The value to search for in the target buffer.
 239
 240   @return The pointer to the first occurrence, or NULL if not found.
 241
 242 **/
 243 CONST VOID *
 244 EFIAPI
 245 InternalMemScanMem64 (
 246   IN      CONST VOID                *Buffer,
 247   IN      UINTN                     Length,
 248   IN      UINT64                    Value
 249   )
 250 {
 251   CONST UINT64                      *Pointer;
 252
 253   Pointer = (CONST UINT64*)Buffer;
 254   do {
 255     if (*(Pointer++) == Value) {
 256       return Pointer;
 257     }
 258   } while (--Length != 0);
 259   return NULL;
 260 }