BaseMemoryLib.h File Reference

Functions
VOID *EFIAPI	CopyMem (OUT VOID *DestinationBuffer, IN CONST VOID *SourceBuffer, IN UINTN Length)
VOID *EFIAPI	SetMem (OUT VOID *Buffer, IN UINTN Length, IN UINT8 Value)
VOID *EFIAPI	SetMem16 (OUT VOID *Buffer, IN UINTN Length, IN UINT16 Value)
VOID *EFIAPI	SetMem32 (OUT VOID *Buffer, IN UINTN Length, IN UINT32 Value)
VOID *EFIAPI	SetMem64 (OUT VOID *Buffer, IN UINTN Length, IN UINT64 Value)
VOID *EFIAPI	SetMemN (OUT VOID *Buffer, IN UINTN Length, IN UINTN Value)
VOID *EFIAPI	ZeroMem (OUT VOID *Buffer, IN UINTN Length)
INTN EFIAPI	CompareMem (IN CONST VOID *DestinationBuffer, IN CONST VOID *SourceBuffer, IN UINTN Length)
VOID *EFIAPI	ScanMem8 (IN CONST VOID *Buffer, IN UINTN Length, IN UINT8 Value)
VOID *EFIAPI	ScanMem16 (IN CONST VOID *Buffer, IN UINTN Length, IN UINT16 Value)
VOID *EFIAPI	ScanMem32 (IN CONST VOID *Buffer, IN UINTN Length, IN UINT32 Value)
VOID *EFIAPI	ScanMem64 (IN CONST VOID *Buffer, IN UINTN Length, IN UINT64 Value)
VOID *EFIAPI	ScanMemN (IN CONST VOID *Buffer, IN UINTN Length, IN UINTN Value)
GUID *EFIAPI	CopyGuid (OUT GUID *DestinationGuid, IN CONST GUID *SourceGuid)
BOOLEAN EFIAPI	CompareGuid (IN CONST GUID *Guid1, IN CONST GUID *Guid2)
VOID *EFIAPI	ScanGuid (IN CONST VOID *Buffer, IN UINTN Length, IN CONST GUID *Guid)
BOOLEAN EFIAPI	IsZeroGuid (IN CONST GUID *Guid)
BOOLEAN EFIAPI	IsZeroBuffer (IN CONST VOID *Buffer, IN UINTN Length)

Detailed Description

Provides copy memory, fill memory, zero memory, and GUID functions.

The Base Memory Library provides optimized implementations for common memory-based operations. These functions should be used in place of coding your own loops to do equivalent common functions. This allows optimized library implementations to help increase performance.

Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Function Documentation

BOOLEAN EFIAPI CompareGuid	(	IN CONST GUID *	Guid1,
		IN CONST GUID *	Guid2
	)

Compares two GUIDs.

This function compares Guid1 to Guid2. If the GUIDs are identical then TRUE is returned. If there are any bit differences in the two GUIDs, then FALSE is returned.

If Guid1 is NULL, then ASSERT(). If Guid2 is NULL, then ASSERT().

Parameters

Guid1	A pointer to a 128 bit GUID.
Guid2	A pointer to a 128 bit GUID.

Return values

TRUE	Guid1 and Guid2 are identical.
FALSE	Guid1 and Guid2 are not identical.

INTN EFIAPI CompareMem	(	IN CONST VOID *	DestinationBuffer,
		IN CONST VOID *	SourceBuffer,
		IN UINTN	Length
	)

Compares the contents of two buffers.

This function compares Length bytes of SourceBuffer to Length bytes of DestinationBuffer. If all Length bytes of the two buffers are identical, then 0 is returned. Otherwise, the value returned is the first mismatched byte in SourceBuffer subtracted from the first mismatched byte in DestinationBuffer.

If Length > 0 and DestinationBuffer is NULL, then ASSERT(). If Length > 0 and SourceBuffer is NULL, then ASSERT(). If Length is greater than (MAX_ADDRESS - DestinationBuffer + 1), then ASSERT(). If Length is greater than (MAX_ADDRESS - SourceBuffer + 1), then ASSERT().

Parameters

DestinationBuffer	The pointer to the destination buffer to compare.
SourceBuffer	The pointer to the source buffer to compare.
Length	The number of bytes to compare.

Returns

0 All Length bytes of the two buffers are identical.

Return values

Non-zero

The first mismatched byte in SourceBuffer subtracted from the first mismatched byte in DestinationBuffer.

GUID* EFIAPI CopyGuid	(	OUT GUID *	DestinationGuid,
		IN CONST GUID *	SourceGuid
	)

Copies a source GUID to a destination GUID.

This function copies the contents of the 128-bit GUID specified by SourceGuid to DestinationGuid, and returns DestinationGuid.

If DestinationGuid is NULL, then ASSERT(). If SourceGuid is NULL, then ASSERT().

Parameters

DestinationGuid	The pointer to the destination GUID.
SourceGuid	The pointer to the source GUID.

Returns

DestinationGuid.

VOID* EFIAPI CopyMem	(	OUT VOID *	DestinationBuffer,
		IN CONST VOID *	SourceBuffer,
		IN UINTN	Length
	)

Copies a source buffer to a destination buffer, and returns the destination buffer.

This function copies Length bytes from SourceBuffer to DestinationBuffer, and returns DestinationBuffer. The implementation must be reentrant, and it must handle the case where SourceBuffer overlaps DestinationBuffer.

If Length is greater than (MAX_ADDRESS - DestinationBuffer + 1), then ASSERT(). If Length is greater than (MAX_ADDRESS - SourceBuffer + 1), then ASSERT().

Parameters

DestinationBuffer	The pointer to the destination buffer of the memory copy.
SourceBuffer	The pointer to the source buffer of the memory copy.
Length	The number of bytes to copy from SourceBuffer to DestinationBuffer.

Returns

DestinationBuffer.

BOOLEAN EFIAPI IsZeroBuffer	(	IN CONST VOID *	Buffer,
		IN UINTN	Length
	)

Checks if the contents of a buffer are all zeros.

This function checks whether the contents of a buffer are all zeros. If the contents are all zeros, return TRUE. Otherwise, return FALSE.

If Length > 0 and Buffer is NULL, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The pointer to the buffer to be checked.
Length	The size of the buffer (in bytes) to be checked.

Return values

TRUE	Contents of the buffer are all zeros.
FALSE	Contents of the buffer are not all zeros.

BOOLEAN EFIAPI IsZeroGuid

(

IN CONST GUID *

Guid

)

Checks if the given GUID is a zero GUID.

This function checks whether the given GUID is a zero GUID. If the GUID is identical to a zero GUID then TRUE is returned. Otherwise, FALSE is returned.

If Guid is NULL, then ASSERT().

Parameters

Guid	The pointer to a 128 bit GUID.

Return values

TRUE	Guid is a zero GUID.
FALSE	Guid is not a zero GUID.

VOID* EFIAPI ScanGuid	(	IN CONST VOID *	Buffer,
		IN UINTN	Length,
		IN CONST GUID *	Guid
	)

Scans a target buffer for a GUID, and returns a pointer to the matching GUID in the target buffer.

This function searches target the buffer specified by Buffer and Length from the lowest address to the highest address at 128-bit increments for the 128-bit GUID value that matches Guid. If a match is found, then a pointer to the matching GUID in the target buffer is returned. If no match is found, then NULL is returned. If Length is 0, then NULL is returned.

If Length > 0 and Buffer is NULL, then ASSERT(). If Buffer is not aligned on a 32-bit boundary, then ASSERT(). If Length is not aligned on a 128-bit boundary, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The pointer to the target buffer to scan.
Length	The number of bytes in Buffer to scan.
Guid	The value to search for in the target buffer.

Returns

A pointer to the matching Guid in the target buffer, otherwise NULL.

VOID* EFIAPI ScanMem16	(	IN CONST VOID *	Buffer,
		IN UINTN	Length,
		IN UINT16	Value
	)

Scans a target buffer for a 16-bit value, and returns a pointer to the matching 16-bit value in the target buffer.

This function searches target the buffer specified by Buffer and Length from the lowest address to the highest address for a 16-bit value that matches Value. If a match is found, then a pointer to the matching byte in the target buffer is returned. If no match is found, then NULL is returned. If Length is 0, then NULL is returned.

If Length > 0 and Buffer is NULL, then ASSERT(). If Buffer is not aligned on a 16-bit boundary, then ASSERT(). If Length is not aligned on a 16-bit boundary, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The pointer to the target buffer to scan.
Length	The number of bytes in Buffer to scan.
Value	The value to search for in the target buffer.

Returns

A pointer to the matching byte in the target buffer, otherwise NULL.

VOID* EFIAPI ScanMem32	(	IN CONST VOID *	Buffer,
		IN UINTN	Length,
		IN UINT32	Value
	)

Scans a target buffer for a 32-bit value, and returns a pointer to the matching 32-bit value in the target buffer.

This function searches target the buffer specified by Buffer and Length from the lowest address to the highest address for a 32-bit value that matches Value. If a match is found, then a pointer to the matching byte in the target buffer is returned. If no match is found, then NULL is returned. If Length is 0, then NULL is returned.

If Length > 0 and Buffer is NULL, then ASSERT(). If Buffer is not aligned on a 32-bit boundary, then ASSERT(). If Length is not aligned on a 32-bit boundary, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The pointer to the target buffer to scan.
Length	The number of bytes in Buffer to scan.
Value	The value to search for in the target buffer.

Returns

A pointer to the matching byte in the target buffer, otherwise NULL.

VOID* EFIAPI ScanMem64	(	IN CONST VOID *	Buffer,
		IN UINTN	Length,
		IN UINT64	Value
	)

Scans a target buffer for a 64-bit value, and returns a pointer to the matching 64-bit value in the target buffer.

This function searches target the buffer specified by Buffer and Length from the lowest address to the highest address for a 64-bit value that matches Value. If a match is found, then a pointer to the matching byte in the target buffer is returned. If no match is found, then NULL is returned. If Length is 0, then NULL is returned.

If Length > 0 and Buffer is NULL, then ASSERT(). If Buffer is not aligned on a 64-bit boundary, then ASSERT(). If Length is not aligned on a 64-bit boundary, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The pointer to the target buffer to scan.
Length	The number of bytes in Buffer to scan.
Value	The value to search for in the target buffer.

Returns

A pointer to the matching byte in the target buffer, otherwise NULL.

VOID* EFIAPI ScanMem8	(	IN CONST VOID *	Buffer,
		IN UINTN	Length,
		IN UINT8	Value
	)

Scans a target buffer for an 8-bit value, and returns a pointer to the matching 8-bit value in the target buffer.

This function searches target the buffer specified by Buffer and Length from the lowest address to the highest address for an 8-bit value that matches Value. If a match is found, then a pointer to the matching byte in the target buffer is returned. If no match is found, then NULL is returned. If Length is 0, then NULL is returned.

If Length > 0 and Buffer is NULL, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The pointer to the target buffer to scan.
Length	The number of bytes in Buffer to scan.
Value	The value to search for in the target buffer.

Returns

A pointer to the matching byte in the target buffer, otherwise NULL.

VOID* EFIAPI ScanMemN	(	IN CONST VOID *	Buffer,
		IN UINTN	Length,
		IN UINTN	Value
	)

Scans a target buffer for a UINTN sized value, and returns a pointer to the matching UINTN sized value in the target buffer.

This function searches target the buffer specified by Buffer and Length from the lowest address to the highest address for a UINTN sized value that matches Value. If a match is found, then a pointer to the matching byte in the target buffer is returned. If no match is found, then NULL is returned. If Length is 0, then NULL is returned.

If Length > 0 and Buffer is NULL, then ASSERT(). If Buffer is not aligned on a UINTN boundary, then ASSERT(). If Length is not aligned on a UINTN boundary, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The pointer to the target buffer to scan.
Length	The number of bytes in Buffer to scan.
Value	The value to search for in the target buffer.

Returns

A pointer to the matching byte in the target buffer, otherwise NULL.

VOID* EFIAPI SetMem	(	OUT VOID *	Buffer,
		IN UINTN	Length,
		IN UINT8	Value
	)

Fills a target buffer with a byte value, and returns the target buffer.

This function fills Length bytes of Buffer with Value, and returns Buffer.

If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The memory to set.
Length	The number of bytes to set.
Value	The value with which to fill Length bytes of Buffer.

Returns

Buffer.

VOID* EFIAPI SetMem16	(	OUT VOID *	Buffer,
		IN UINTN	Length,
		IN UINT16	Value
	)

Fills a target buffer with a 16-bit value, and returns the target buffer.

This function fills Length bytes of Buffer with the 16-bit value specified by Value, and returns Buffer. Value is repeated every 16-bits in for Length bytes of Buffer.

If Length > 0 and Buffer is NULL, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). If Buffer is not aligned on a 16-bit boundary, then ASSERT(). If Length is not aligned on a 16-bit boundary, then ASSERT().

Parameters

Buffer	The pointer to the target buffer to fill.
Length	The number of bytes in Buffer to fill.
Value	The value with which to fill Length bytes of Buffer.

Returns

Buffer.

VOID* EFIAPI SetMem32	(	OUT VOID *	Buffer,
		IN UINTN	Length,
		IN UINT32	Value
	)

Fills a target buffer with a 32-bit value, and returns the target buffer.

This function fills Length bytes of Buffer with the 32-bit value specified by Value, and returns Buffer. Value is repeated every 32-bits in for Length bytes of Buffer.

If Length > 0 and Buffer is NULL, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). If Buffer is not aligned on a 32-bit boundary, then ASSERT(). If Length is not aligned on a 32-bit boundary, then ASSERT().

Parameters

Buffer	The pointer to the target buffer to fill.
Length	The number of bytes in Buffer to fill.
Value	The value with which to fill Length bytes of Buffer.

Returns

Buffer.

VOID* EFIAPI SetMem64	(	OUT VOID *	Buffer,
		IN UINTN	Length,
		IN UINT64	Value
	)

Fills a target buffer with a 64-bit value, and returns the target buffer.

This function fills Length bytes of Buffer with the 64-bit value specified by Value, and returns Buffer. Value is repeated every 64-bits in for Length bytes of Buffer.

If Length > 0 and Buffer is NULL, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). If Buffer is not aligned on a 64-bit boundary, then ASSERT(). If Length is not aligned on a 64-bit boundary, then ASSERT().

Parameters

Buffer	The pointer to the target buffer to fill.
Length	The number of bytes in Buffer to fill.
Value	The value with which to fill Length bytes of Buffer.

Returns

Buffer.

VOID* EFIAPI SetMemN	(	OUT VOID *	Buffer,
		IN UINTN	Length,
		IN UINTN	Value
	)

Fills a target buffer with a value that is size UINTN, and returns the target buffer.

This function fills Length bytes of Buffer with the UINTN sized value specified by Value, and returns Buffer. Value is repeated every sizeof(UINTN) bytes for Length bytes of Buffer.

If Length > 0 and Buffer is NULL, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT(). If Buffer is not aligned on a UINTN boundary, then ASSERT(). If Length is not aligned on a UINTN boundary, then ASSERT().

Parameters

Buffer	The pointer to the target buffer to fill.
Length	The number of bytes in Buffer to fill.
Value	The value with which to fill Length bytes of Buffer.

Returns

Buffer.

VOID* EFIAPI ZeroMem	(	OUT VOID *	Buffer,
		IN UINTN	Length
	)

Fills a target buffer with zeros, and returns the target buffer.

This function fills Length bytes of Buffer with zeros, and returns Buffer.

If Length > 0 and Buffer is NULL, then ASSERT(). If Length is greater than (MAX_ADDRESS - Buffer + 1), then ASSERT().

Parameters

Buffer	The pointer to the target buffer to fill with zeros.
Length	The number of bytes in Buffer to fill with zeros.

Returns

Buffer.