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[mirror_edk2.git] / MdePkg / Library / BaseLib / Unaligned.c

/** @file\r
  Unaligned access functions of BaseLib.\r
\r
  Copyright (c) 2006, Intel Corporation\r
  All rights reserved. This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
//\r
// Include common header file for this module.\r
//\r
#include <BaseLibInternals.h>\r
\r
\r
/**\r
  Reads a 16-bit value from memory that may be unaligned.\r
\r
  This function returns the 16-bit value pointed to by Buffer. The function\r
  guarantees that the read operation does not produce an alignment fault.\r
\r
  If the Buffer is NULL, then ASSERT().\r
\r
  @param  Buffer  Pointer to a 16-bit value that may be unaligned.\r
\r
  @return Data read from Buffer.\r
\r
**/\r
UINT16\r
EFIAPI\r
ReadUnaligned16 (\r
  IN      CONST UINT16              *Buffer\r
  )\r
{\r
  ASSERT (Buffer != NULL);\r
\r
  return *Buffer;\r
}\r
\r
/**\r
  Writes a 16-bit value to memory that may be unaligned.\r
\r
  This function writes the 16-bit value specified by Value to Buffer. Value is\r
  returned. The function guarantees that the write operation does not produce\r
  an alignment fault.\r
\r
  If the Buffer is NULL, then ASSERT().\r
\r
  @param  Buffer  Pointer to a 16-bit value that may be unaligned.\r
  @param  Value   16-bit value to write to Buffer.\r
\r
  @return Value written to Buffer\r
\r
**/\r
UINT16\r
EFIAPI\r
WriteUnaligned16 (\r
  OUT     UINT16                    *Buffer,\r
  IN      UINT16                    Value\r
  )\r
{\r
  ASSERT (Buffer != NULL);\r
\r
  return *Buffer = Value;\r
}\r
\r
/**\r
  Reads a 24-bit value from memory that may be unaligned.\r
\r
  This function returns the 24-bit value pointed to by Buffer. The function\r
  guarantees that the read operation does not produce an alignment fault.\r
\r
  If the Buffer is NULL, then ASSERT().\r
\r
  @param  Buffer  Pointer to a 24-bit value that may be unaligned.\r
\r
  @return The value read from Buffer.\r
\r
**/\r
UINT32\r
EFIAPI\r
ReadUnaligned24 (\r
  IN      CONST UINT32              *Buffer\r
  )\r
{\r
  ASSERT (Buffer != NULL);\r
\r
  return *Buffer & 0xffffff;\r
}\r
\r
/**\r
  Writes a 24-bit value to memory that may be unaligned.\r
\r
  This function writes the 24-bit value specified by Value to Buffer. Value is\r
  returned. The function guarantees that the write operation does not produce\r
  an alignment fault.\r
\r
  If the Buffer is NULL, then ASSERT().\r
\r
  @param  Buffer  Pointer to a 24-bit value that may be unaligned.\r
  @param  Value   24-bit value to write to Buffer.\r
\r
  @return The value written to Buffer.\r
\r
**/\r
UINT32\r
EFIAPI\r
WriteUnaligned24 (\r
  OUT     UINT32                    *Buffer,\r
  IN      UINT32                    Value\r
  )\r
{\r
  ASSERT (Buffer != NULL);\r
\r
  *Buffer = BitFieldWrite32 (*Buffer, 0, 23, Value);\r
  return Value;\r
}\r
\r
/**\r
  Reads a 32-bit value from memory that may be unaligned.\r
\r
  This function returns the 32-bit value pointed to by Buffer. The function\r
  guarantees that the read operation does not produce an alignment fault.\r
\r
  If the Buffer is NULL, then ASSERT().\r
\r
  @param  Buffer  Pointer to a 32-bit value that may be unaligned.\r
\r
  @return Data read from Buffer.\r
\r
**/\r
UINT32\r
EFIAPI\r
ReadUnaligned32 (\r
  IN      CONST UINT32              *Buffer\r
  )\r
{\r
  ASSERT (Buffer != NULL);\r
\r
  return *Buffer;\r
}\r
\r
/**\r
  Writes a 32-bit value to memory that may be unaligned.\r
\r
  This function writes the 32-bit value specified by Value to Buffer. Value is\r
  returned. The function guarantees that the write operation does not produce\r
  an alignment fault.\r
\r
  If the Buffer is NULL, then ASSERT().\r
\r
  @param  Buffer  Pointer to a 32-bit value that may be unaligned.\r
  @param  Value   32-bit value to write to Buffer.\r
\r
  @return Value written to Buffer\r
\r
**/\r
UINT32\r
EFIAPI\r
WriteUnaligned32 (\r
  OUT     UINT32                    *Buffer,\r
  IN      UINT32                    Value\r
  )\r
{\r
  ASSERT (Buffer != NULL);\r
\r
  return *Buffer = Value;\r
}\r
\r
/**\r
  Reads a 64-bit value from memory that may be unaligned.\r
\r
  This function returns the 64-bit value pointed to by Buffer. The function\r
  guarantees that the read operation does not produce an alignment fault.\r
\r
  If the Buffer is NULL, then ASSERT().\r
\r
  @param  Buffer  Pointer to a 64-bit value that may be unaligned.\r
\r
  @return Data read from Buffer.\r
\r
**/\r
UINT64\r
EFIAPI\r
ReadUnaligned64 (\r
  IN      CONST UINT64              *Buffer\r
  )\r
{\r
  ASSERT (Buffer != NULL);\r
\r
  return *Buffer;\r
}\r
\r
/**\r
  Writes a 64-bit value to memory that may be unaligned.\r
\r
  This function writes the 64-bit value specified by Value to Buffer. Value is\r
  returned. The function guarantees that the write operation does not produce\r
  an alignment fault.\r
\r
  If the Buffer is NULL, then ASSERT().\r
\r
  @param  Buffer  Pointer to a 64-bit value that may be unaligned.\r
  @param  Value   64-bit value to write to Buffer.\r
\r
  @return Value written to Buffer.\r
\r
**/\r
UINT64\r
EFIAPI\r
WriteUnaligned64 (\r
  OUT     UINT64                    *Buffer,\r
  IN      UINT64                    Value\r
  )\r
{\r
  ASSERT (Buffer != NULL);\r
\r
  return *Buffer = Value;\r
}\r