diff options
Diffstat (limited to 'Core/MdePkg/Library/BaseLib/Arm/Unaligned.c')
| -rw-r--r-- | Core/MdePkg/Library/BaseLib/Arm/Unaligned.c | 252 |
1 files changed, 252 insertions, 0 deletions
diff --git a/Core/MdePkg/Library/BaseLib/Arm/Unaligned.c b/Core/MdePkg/Library/BaseLib/Arm/Unaligned.c new file mode 100644 index 0000000000..34f1732a76 --- /dev/null +++ b/Core/MdePkg/Library/BaseLib/Arm/Unaligned.c @@ -0,0 +1,252 @@ +/** @file
+ Unaligned access functions of BaseLib for ARM.
+
+ volatile was added to work around optimization issues.
+
+ Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+ Portions copyright (c) 2008 - 2009, Apple Inc. All rights reserved.<BR>
+ This program and the accompanying materials
+ are licensed and made available under the terms and conditions of the BSD License
+ which accompanies this distribution. The full text of the license may be found at
+ http://opensource.org/licenses/bsd-license.php.
+
+ THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include "BaseLibInternals.h"
+
+/**
+ Reads a 16-bit value from memory that may be unaligned.
+
+ This function returns the 16-bit value pointed to by Buffer. The function
+ guarantees that the read operation does not produce an alignment fault.
+
+ If the Buffer is NULL, then ASSERT().
+
+ @param Buffer The pointer to a 16-bit value that may be unaligned.
+
+ @return The 16-bit value read from Buffer.
+
+**/
+UINT16
+EFIAPI
+ReadUnaligned16 (
+ IN CONST UINT16 *Buffer
+ )
+{
+ volatile UINT8 LowerByte;
+ volatile UINT8 HigherByte;
+
+ ASSERT (Buffer != NULL);
+
+ LowerByte = ((UINT8*)Buffer)[0];
+ HigherByte = ((UINT8*)Buffer)[1];
+
+ return (UINT16)(LowerByte | (HigherByte << 8));
+}
+
+/**
+ Writes a 16-bit value to memory that may be unaligned.
+
+ This function writes the 16-bit value specified by Value to Buffer. Value is
+ returned. The function guarantees that the write operation does not produce
+ an alignment fault.
+
+ If the Buffer is NULL, then ASSERT().
+
+ @param Buffer The pointer to a 16-bit value that may be unaligned.
+ @param Value 16-bit value to write to Buffer.
+
+ @return The 16-bit value to write to Buffer.
+
+**/
+UINT16
+EFIAPI
+WriteUnaligned16 (
+ OUT UINT16 *Buffer,
+ IN UINT16 Value
+ )
+{
+ ASSERT (Buffer != NULL);
+
+ ((volatile UINT8*)Buffer)[0] = (UINT8)Value;
+ ((volatile UINT8*)Buffer)[1] = (UINT8)(Value >> 8);
+
+ return Value;
+}
+
+/**
+ Reads a 24-bit value from memory that may be unaligned.
+
+ This function returns the 24-bit value pointed to by Buffer. The function
+ guarantees that the read operation does not produce an alignment fault.
+
+ If the Buffer is NULL, then ASSERT().
+
+ @param Buffer The pointer to a 24-bit value that may be unaligned.
+
+ @return The 24-bit value read from Buffer.
+
+**/
+UINT32
+EFIAPI
+ReadUnaligned24 (
+ IN CONST UINT32 *Buffer
+ )
+{
+ ASSERT (Buffer != NULL);
+
+ return (UINT32)(
+ ReadUnaligned16 ((UINT16*)Buffer) |
+ (((UINT8*)Buffer)[2] << 16)
+ );
+}
+
+/**
+ Writes a 24-bit value to memory that may be unaligned.
+
+ This function writes the 24-bit value specified by Value to Buffer. Value is
+ returned. The function guarantees that the write operation does not produce
+ an alignment fault.
+
+ If the Buffer is NULL, then ASSERT().
+
+ @param Buffer The pointer to a 24-bit value that may be unaligned.
+ @param Value 24-bit value to write to Buffer.
+
+ @return The 24-bit value to write to Buffer.
+
+**/
+UINT32
+EFIAPI
+WriteUnaligned24 (
+ OUT UINT32 *Buffer,
+ IN UINT32 Value
+ )
+{
+ ASSERT (Buffer != NULL);
+
+ WriteUnaligned16 ((UINT16*)Buffer, (UINT16)Value);
+ *(UINT8*)((UINT16*)Buffer + 1) = (UINT8)(Value >> 16);
+ return Value;
+}
+
+/**
+ Reads a 32-bit value from memory that may be unaligned.
+
+ This function returns the 32-bit value pointed to by Buffer. The function
+ guarantees that the read operation does not produce an alignment fault.
+
+ If the Buffer is NULL, then ASSERT().
+
+ @param Buffer The pointer to a 32-bit value that may be unaligned.
+
+ @return The 32-bit value read from Buffer.
+
+**/
+UINT32
+EFIAPI
+ReadUnaligned32 (
+ IN CONST UINT32 *Buffer
+ )
+{
+ UINT16 LowerBytes;
+ UINT16 HigherBytes;
+
+ ASSERT (Buffer != NULL);
+
+ LowerBytes = ReadUnaligned16 ((UINT16*) Buffer);
+ HigherBytes = ReadUnaligned16 ((UINT16*) Buffer + 1);
+
+ return (UINT32) (LowerBytes | (HigherBytes << 16));
+}
+
+/**
+ Writes a 32-bit value to memory that may be unaligned.
+
+ This function writes the 32-bit value specified by Value to Buffer. Value is
+ returned. The function guarantees that the write operation does not produce
+ an alignment fault.
+
+ If the Buffer is NULL, then ASSERT().
+
+ @param Buffer The pointer to a 32-bit value that may be unaligned.
+ @param Value 32-bit value to write to Buffer.
+
+ @return The 32-bit value to write to Buffer.
+
+**/
+UINT32
+EFIAPI
+WriteUnaligned32 (
+ OUT UINT32 *Buffer,
+ IN UINT32 Value
+ )
+{
+ ASSERT (Buffer != NULL);
+
+ WriteUnaligned16 ((UINT16*)Buffer, (UINT16)Value);
+ WriteUnaligned16 ((UINT16*)Buffer + 1, (UINT16)(Value >> 16));
+ return Value;
+}
+
+/**
+ Reads a 64-bit value from memory that may be unaligned.
+
+ This function returns the 64-bit value pointed to by Buffer. The function
+ guarantees that the read operation does not produce an alignment fault.
+
+ If the Buffer is NULL, then ASSERT().
+
+ @param Buffer The pointer to a 64-bit value that may be unaligned.
+
+ @return The 64-bit value read from Buffer.
+
+**/
+UINT64
+EFIAPI
+ReadUnaligned64 (
+ IN CONST UINT64 *Buffer
+ )
+{
+ UINT32 LowerBytes;
+ UINT32 HigherBytes;
+
+ ASSERT (Buffer != NULL);
+
+ LowerBytes = ReadUnaligned32 ((UINT32*) Buffer);
+ HigherBytes = ReadUnaligned32 ((UINT32*) Buffer + 1);
+
+ return (UINT64) (LowerBytes | LShiftU64 (HigherBytes, 32));
+}
+
+/**
+ Writes a 64-bit value to memory that may be unaligned.
+
+ This function writes the 64-bit value specified by Value to Buffer. Value is
+ returned. The function guarantees that the write operation does not produce
+ an alignment fault.
+
+ If the Buffer is NULL, then ASSERT().
+
+ @param Buffer The pointer to a 64-bit value that may be unaligned.
+ @param Value 64-bit value to write to Buffer.
+
+ @return The 64-bit value to write to Buffer.
+
+**/
+UINT64
+EFIAPI
+WriteUnaligned64 (
+ OUT UINT64 *Buffer,
+ IN UINT64 Value
+ )
+{
+ ASSERT (Buffer != NULL);
+
+ WriteUnaligned32 ((UINT32*)Buffer, (UINT32)Value);
+ WriteUnaligned32 ((UINT32*)Buffer + 1, (UINT32)RShiftU64 (Value, 32));
+ return Value;
+}
|