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 - 2016, 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     ++Pointer;
 169   } while (--Length != 0);
 170   return NULL;
 171 }
 172
 173 /**
 174   Scans a target buffer for a 16-bit value, and returns a pointer to the
 175   matching 16-bit value in the target buffer.
 176
 177   @param  Buffer  The pointer to the target buffer to scan.
 178   @param  Length  The count of 16-bit value to scan. Must be non-zero.
 179   @param  Value   The value to search for in the target buffer.
 180
 181   @return The pointer to the first occurrence, or NULL if not found.
 182
 183 **/
 184 CONST VOID *
 185 EFIAPI
 186 InternalMemScanMem16 (
 187   IN      CONST VOID                *Buffer,
 188   IN      UINTN                     Length,
 189   IN      UINT16                    Value
 190   )
 191 {
 192   CONST UINT16                      *Pointer;
 193
 194   Pointer = (CONST UINT16*)Buffer;
 195   do {
 196     if (*Pointer == Value) {
 197       return Pointer;
 198     }
 199     ++Pointer;
 200   } while (--Length != 0);
 201   return NULL;
 202 }
 203
 204 /**
 205   Scans a target buffer for a 32-bit value, and returns a pointer to the
 206   matching 32-bit value in the target buffer.
 207
 208   @param  Buffer  The pointer to the target buffer to scan.
 209   @param  Length  The count of 32-bit value to scan. Must be non-zero.
 210   @param  Value   The value to search for in the target buffer.
 211
 212   @return The pointer to the first occurrence, or NULL if not found.
 213
 214 **/
 215 CONST VOID *
 216 EFIAPI
 217 InternalMemScanMem32 (
 218   IN      CONST VOID                *Buffer,
 219   IN      UINTN                     Length,
 220   IN      UINT32                    Value
 221   )
 222 {
 223   CONST UINT32                      *Pointer;
 224
 225   Pointer = (CONST UINT32*)Buffer;
 226   do {
 227     if (*Pointer == Value) {
 228       return Pointer;
 229     }
 230     ++Pointer;
 231   } while (--Length != 0);
 232   return NULL;
 233 }
 234
 235 /**
 236   Scans a target buffer for a 64-bit value, and returns a pointer to the
 237   matching 64-bit value in the target buffer.
 238
 239   @param  Buffer  The pointer to the target buffer to scan.
 240   @param  Length  The count of 64-bit value to scan. Must be non-zero.
 241   @param  Value   The value to search for in the target buffer.
 242
 243   @return The pointer to the first occurrence, or NULL if not found.
 244
 245 **/
 246 CONST VOID *
 247 EFIAPI
 248 InternalMemScanMem64 (
 249   IN      CONST VOID                *Buffer,
 250   IN      UINTN                     Length,
 251   IN      UINT64                    Value
 252   )
 253 {
 254   CONST UINT64                      *Pointer;
 255
 256   Pointer = (CONST UINT64*)Buffer;
 257   do {
 258     if (*Pointer == Value) {
 259       return Pointer;
 260     }
 261     ++Pointer;
 262   } while (--Length != 0);
 263   return NULL;
 264 }
 265
 266 /**
 267   Checks whether the contents of a buffer are all zeros.
 268
 269   @param  Buffer  The pointer to the buffer to be checked.
 270   @param  Length  The size of the buffer (in bytes) to be checked.
 271
 272   @retval TRUE    Contents of the buffer are all zeros.
 273   @retval FALSE   Contents of the buffer are not all zeros.
 274
 275 **/
 276 BOOLEAN
 277 EFIAPI
 278 InternalMemIsZeroBuffer (
 279   IN CONST VOID  *Buffer,
 280   IN UINTN       Length
 281   )
 282 {
 283   CONST UINT8 *BufferData;
 284   UINTN       Index;
 285
 286   BufferData = Buffer;
 287   for (Index = 0; Index < Length; Index++) {
 288     if (BufferData[Index] != 0) {
 289       return FALSE;
 290     }
 291   }
 292   return TRUE;
 293 }