Functions
EFI_FILE_INFO *EFIAPI	FileHandleGetInfo (IN EFI_FILE_HANDLE FileHandle)

EFI_STATUS EFIAPI	FileHandleSetInfo (IN EFI_FILE_HANDLE FileHandle, IN CONST EFI_FILE_INFO *FileInfo)

EFI_STATUS EFIAPI	FileHandleRead (IN EFI_FILE_HANDLE FileHandle, IN OUT UINTN BufferSize, OUT VOID Buffer)

EFI_STATUS EFIAPI	FileHandleWrite (IN EFI_FILE_HANDLE FileHandle, IN OUT UINTN BufferSize, IN VOID Buffer)

EFI_STATUS EFIAPI	FileHandleClose (IN EFI_FILE_HANDLE FileHandle)

EFI_STATUS EFIAPI	FileHandleDelete (IN EFI_FILE_HANDLE FileHandle)

EFI_STATUS EFIAPI	FileHandleSetPosition (IN EFI_FILE_HANDLE FileHandle, IN UINT64 Position)

EFI_STATUS EFIAPI	FileHandleGetPosition (IN EFI_FILE_HANDLE FileHandle, OUT UINT64 *Position)

EFI_STATUS EFIAPI	FileHandleFlush (IN EFI_FILE_HANDLE FileHandle)

EFI_STATUS EFIAPI	FileHandleIsDirectory (IN EFI_FILE_HANDLE DirHandle)

EFI_STATUS EFIAPI	FileHandleFindFirstFile (IN EFI_FILE_HANDLE DirHandle, OUT EFI_FILE_INFO **Buffer)

EFI_STATUS EFIAPI	FileHandleFindNextFile (IN EFI_FILE_HANDLE DirHandle, OUT EFI_FILE_INFO Buffer, OUT BOOLEAN NoFile)

EFI_STATUS EFIAPI	FileHandleGetSize (IN EFI_FILE_HANDLE FileHandle, OUT UINT64 *Size)

EFI_STATUS EFIAPI	FileHandleSetSize (IN EFI_FILE_HANDLE FileHandle, IN UINT64 Size)

EFI_STATUS EFIAPI	FileHandleGetFileName (IN CONST EFI_FILE_HANDLE Handle, OUT CHAR16 **FullFileName)

EFI_STATUS EFIAPI	FileHandleReadLine (IN EFI_FILE_HANDLE Handle, IN OUT CHAR16 Buffer, IN OUT UINTN Size, IN BOOLEAN Truncate, IN OUT BOOLEAN *Ascii)

CHAR16 *EFIAPI	FileHandleReturnLine (IN EFI_FILE_HANDLE Handle, IN OUT BOOLEAN *Ascii)

EFI_STATUS EFIAPI	FileHandleWriteLine (IN EFI_FILE_HANDLE Handle, IN CHAR16 *Buffer)

EFI_STATUS EFIAPI	FileHandlePrintLine (IN EFI_FILE_HANDLE Handle, IN CONST CHAR16 *Format,...)

BOOLEAN EFIAPI	FileHandleEof (IN EFI_FILE_HANDLE Handle)

Variables
CONST UINT16	gUnicodeFileTag

Detailed Description

Provides interface to EFI_FILE_HANDLE functionality.

Copyright (c) 2009 - 2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Function Documentation

EFI_STATUS EFIAPI FileHandleClose ( IN EFI_FILE_HANDLE FileHandle )

Close an open file handle.

This function closes a specified file handle. All "dirty" cached file data is flushed to the device, and the file is closed. In all cases the handle is closed.

Parameters

[in] FileHandle The file handle to close.

Return values

EFI_SUCCESS The file handle was closed successfully.

EFI_STATUS EFIAPI FileHandleDelete ( IN EFI_FILE_HANDLE FileHandle )

Delete a file and close the handle.

This function closes and deletes a file. In all cases the file handle is closed. If the file cannot be deleted, the warning code EFI_WARN_DELETE_FAILURE is returned, but the handle is still closed.

Parameters

[in] FileHandle The file handle to delete.

Return values

EFI_SUCCESS	The file was closed successfully.
EFI_WARN_DELETE_FAILURE	The handle was closed, but the file was not deleted.
INVALID_PARAMETER	One of the parameters has an invalid value.

BOOLEAN EFIAPI FileHandleEof ( IN EFI_FILE_HANDLE Handle )

Function to determine if a FILE_HANDLE is at the end of the file.

This will NOT work on directories.

If Handle is NULL, then ASSERT().

Parameters

[in] Handle The file handle.

Return values

TRUE	The position is at the end of the file.
FALSE	The position is not at the end of the file.

EFI_STATUS EFIAPI FileHandleFindFirstFile	(	IN EFI_FILE_HANDLE	DirHandle,
		OUT EFI_FILE_INFO **	Buffer
	)

Retrieve first entry from a directory.

This function takes an open directory handle and gets information from the first entry in the directory. A buffer is allocated to contain the information and a pointer to the buffer is returned in *Buffer. The caller can use FileHandleFindNextFile() to get subsequent directory entries.

The buffer will be freed by FileHandleFindNextFile() when the last directory entry is read. Otherwise, the caller must free the buffer, using FreePool, when finished with it.

Parameters

[in]	DirHandle	The file handle of the directory to search.
[out]	Buffer	The pointer to pointer to buffer for file's information.

Return values

EFI_SUCCESS	Found the first file.
EFI_NOT_FOUND	Cannot find the directory.
EFI_NO_MEDIA	The device has no media.
EFI_DEVICE_ERROR	The device reported an error.
EFI_VOLUME_CORRUPTED	The file system structures are corrupted.

Returns: Others The status of FileHandleGetInfo, FileHandleSetPosition, or FileHandleRead.

EFI_STATUS EFIAPI FileHandleFindNextFile	(	IN EFI_FILE_HANDLE	DirHandle,
		OUT EFI_FILE_INFO *	Buffer,
		OUT BOOLEAN *	NoFile
	)

Retrieve next entries from a directory.

To use this function, the caller must first call the FileHandleFindFirstFile() function to get the first directory entry. Subsequent directory entries are retrieved by using the FileHandleFindNextFile() function. This function can be called several times to get each entry from the directory. If the call of FileHandleFindNextFile() retrieved the last directory entry, the next call of this function will set *NoFile to TRUE and free the buffer.

Parameters

[in]	DirHandle	The file handle of the directory.
[out]	Buffer	The pointer to buffer for file's information.
[out]	NoFile	The pointer to boolean when last file is found.

Return values

EFI_SUCCESS	Found the next file, or reached last file.
EFI_NO_MEDIA	The device has no media.
EFI_DEVICE_ERROR	The device reported an error.
EFI_VOLUME_CORRUPTED	The file system structures are corrupted.

EFI_STATUS EFIAPI FileHandleFlush ( IN EFI_FILE_HANDLE FileHandle )

Flushes data on a file.

This function flushes all modified data associated with a file to a device.

Parameters

[in] FileHandle The file handle on which to flush data.

Return values

EFI_SUCCESS	The data was flushed.
EFI_NO_MEDIA	The device has no media.
EFI_DEVICE_ERROR	The device reported an error.
EFI_VOLUME_CORRUPTED	The file system structures are corrupted.
EFI_WRITE_PROTECTED	The file or medium is write protected.
EFI_ACCESS_DENIED	The file was opened for read only.

EFI_STATUS EFIAPI FileHandleGetFileName	(	IN CONST EFI_FILE_HANDLE	Handle,
		OUT CHAR16 **	FullFileName
	)

Function to get a full filename given a EFI_FILE_HANDLE somewhere lower on the directory 'stack'. If the file is a directory, then append the '\' char at the end of name string. If it's not a directory, then the last '\' should not be added.

Parameters

[in]	Handle	Handle to the Directory or File to create path to.
[out]	FullFileName	Pointer to pointer to generated full file name. It is the responsibility of the caller to free this memory with a call to FreePool().

Return values

EFI_SUCCESS	The operation was successful and FullFileName is valid.
EFI_INVALID_PARAMETER	Handle was NULL.
EFI_INVALID_PARAMETER	FullFileName was NULL.
EFI_OUT_OF_MEMORY	A memory allocation failed.

EFI_FILE_INFO* EFIAPI FileHandleGetInfo ( IN EFI_FILE_HANDLE FileHandle )

This function retrieves information about the file for the handle specified and stores it in the allocated pool memory.

This function allocates a buffer to store the file's information. It is the caller's responsibility to free the buffer.

Parameters

[in] FileHandle The file handle of the file for which information is being requested.

Return values

NULL	Information could not be retrieved.
!NULL	The information about the file.

EFI_STATUS EFIAPI FileHandleGetPosition	(	IN EFI_FILE_HANDLE	FileHandle,
		OUT UINT64 *	Position
	)

Gets a file's current position.

This function retrieves the current file position for the file handle. For directories, the current file position has no meaning outside of the file system driver. As such, the operation is not supported. An error is returned if FileHandle is a directory.

Parameters

[in]	FileHandle	The open file handle on which to get the position.
[out]	Position	The byte position from beginning of file.

Return values

EFI_SUCCESS	The operation completed successfully.
INVALID_PARAMETER	One of the parameters has an invalid value.
EFI_UNSUPPORTED	The request is not valid on directories.

EFI_STATUS EFIAPI FileHandleGetSize	(	IN EFI_FILE_HANDLE	FileHandle,
		OUT UINT64 *	Size
	)

Retrieve the size of a file.

This function extracts the file size info from the FileHandle's EFI_FILE_INFO data.

Parameters

[in]	FileHandle	The file handle from which size is retrieved.
[out]	Size	The pointer to size.

Return values

EFI_SUCCESS	Operation was completed successfully.
EFI_DEVICE_ERROR	Cannot access the file.
EFI_INVALID_PARAMETER	FileHandle is NULL. Size is NULL.

EFI_STATUS EFIAPI FileHandleIsDirectory ( IN EFI_FILE_HANDLE DirHandle )

Function to determine if a given handle is a directory handle.

Open the file information on the DirHandle and verify that the Attribute includes EFI_FILE_DIRECTORY bit set.

Parameters

[in] DirHandle Handle to open file.

Return values

EFI_SUCCESS	DirHandle is a directory.
EFI_INVALID_PARAMETER	DirHandle is NULL. The file information returns from FileHandleGetInfo is NULL.
EFI_NOT_FOUND	DirHandle is not a directory.

EFI_STATUS EFIAPI FileHandlePrintLine	(	IN EFI_FILE_HANDLE	Handle,
		IN CONST CHAR16 *	Format,
			...
	)

Function to take a formatted argument and print it to a file.

Parameters

[in]	Handle	The file handle for the file to write to.
[in]	Format	The format argument (see printlib for the format specifier).
[in]	...	The variable arguments for the format.

Return values

EFI_SUCCESS	The operation was successful.
other	A return value from FileHandleWriteLine.

See Also: FileHandleWriteLine

EFI_STATUS EFIAPI FileHandleRead	(	IN EFI_FILE_HANDLE	FileHandle,
		IN OUT UINTN *	BufferSize,
		OUT VOID *	Buffer
	)

This function reads information from an opened file.

If FileHandle is not a directory, the function reads the requested number of bytes from the file at the file's current position and returns them in Buffer. If the read goes beyond the end of the file, the read length is truncated to the end of the file. The file's current position is increased by the number of bytes returned. If FileHandle is a directory, the function reads the directory entry at the file's current position and returns the entry in Buffer. If the Buffer is not large enough to hold the current directory entry, then EFI_BUFFER_TOO_SMALL is returned and the current file position is not updated. BufferSize is set to be the size of the buffer needed to read the entry. On success, the current position is updated to the next directory entry. If there are no more directory entries, the read returns a zero-length buffer. EFI_FILE_INFO is the structure returned as the directory entry.

Parameters

[in]	FileHandle	The opened file handle.
[in,out]	BufferSize	On input, the size of buffer in bytes. On return, the number of bytes written.
[out]	Buffer	The buffer to put read data into.

Return values

EFI_SUCCESS	Data was read.
EFI_NO_MEDIA	The device has no media.
EFI_DEVICE_ERROR	The device reported an error.
EFI_VOLUME_CORRUPTED	The file system structures are corrupted.
EFI_BUFFER_TO_SMALL	Buffer is too small. ReadSize contains required size.

EFI_STATUS EFIAPI FileHandleReadLine	(	IN EFI_FILE_HANDLE	Handle,
		IN OUT CHAR16 *	Buffer,
		IN OUT UINTN *	Size,
		IN BOOLEAN	Truncate,
		IN OUT BOOLEAN *	Ascii
	)

Function to read a single line (up to but not including the
) from a file.

If the position upon start is 0, then the Ascii Boolean will be set. This should be maintained and not changed for all operations with the same file. The function will not return the and
character in buffer. When an empty line is read a CHAR_NULL character will be returned in buffer.

Parameters

[in]	Handle	FileHandle to read from.
[in,out]	Buffer	The pointer to buffer to read into.
[in,out]	Size	The pointer to number of bytes in Buffer.
[in]	Truncate	If the buffer is large enough, this has no effect. If the buffer is is too small and Truncate is TRUE, the line will be truncated. If the buffer is is too small and Truncate is FALSE, then no read will occur.
[in,out]	Ascii	Boolean value for indicating whether the file is Ascii (TRUE) or UCS2 (FALSE).

Return values

EFI_SUCCESS	The operation was successful. The line is stored in Buffer.
EFI_INVALID_PARAMETER	Handle was NULL.
EFI_INVALID_PARAMETER	Size was NULL.
EFI_BUFFER_TOO_SMALL	Size was not large enough to store the line. Size was updated to the minimum space required.

See Also: FileHandleRead

CHAR16* EFIAPI FileHandleReturnLine	(	IN EFI_FILE_HANDLE	Handle,
		IN OUT BOOLEAN *	Ascii
	)

Function to read a single line from a file. The
is not included in the returned buffer. The returned buffer must be callee freed.

If the position upon start is 0, then the Ascii Boolean will be set. This should be maintained and not changed for all operations with the same file.

Parameters

[in]	Handle	FileHandle to read from.
[in,out]	Ascii	Boolean value for indicating whether the file is Ascii (TRUE) or UCS2 (FALSE).

Returns: The line of text from the file.

See Also: FileHandleReadLine

EFI_STATUS EFIAPI FileHandleSetInfo	(	IN EFI_FILE_HANDLE	FileHandle,
		IN CONST EFI_FILE_INFO *	FileInfo
	)

This function sets the information about the file for the opened handle specified.

Parameters

[in]	FileHandle	The file handle of the file for which information is being set.
[in]	FileInfo	The information to set.

Return values

EFI_SUCCESS	The information was set.
EFI_INVALID_PARAMETER	A parameter was out of range or invalid.
EFI_UNSUPPORTED	The FileHandle does not support FileInfo.
EFI_NO_MEDIA	The device has no medium.
EFI_DEVICE_ERROR	The device reported an error.
EFI_VOLUME_CORRUPTED	The file system structures are corrupted.
EFI_WRITE_PROTECTED	The file or medium is write protected.
EFI_ACCESS_DENIED	The file was opened read only.
EFI_VOLUME_FULL	The volume is full.

EFI_STATUS EFIAPI FileHandleSetPosition	(	IN EFI_FILE_HANDLE	FileHandle,
		IN UINT64	Position
	)

Set the current position in a file.

This function sets the current file position for the handle to the position supplied. With the exception of moving to position 0xFFFFFFFFFFFFFFFF, only absolute positioning is supported, and moving past the end of the file is allowed (a subsequent write would grow the file). Moving to position 0xFFFFFFFFFFFFFFFF causes the current position to be set to the end of the file. If FileHandle is a directory, the only position that may be set is zero. This has the effect of starting the read process of the directory entries over again.

Parameters

[in]	FileHandle	The file handle on which the position is being set.
[in]	Position	The byte position from the beginning of the file.

Return values

EFI_SUCCESS	The operation completed successfully.
EFI_UNSUPPORTED	The request for non-zero is not valid on directories.
INVALID_PARAMETER	One of the parameters has an invalid value.

EFI_STATUS EFIAPI FileHandleSetSize	(	IN EFI_FILE_HANDLE	FileHandle,
		IN UINT64	Size
	)

Set the size of a file.

This function changes the file size info from the FileHandle's EFI_FILE_INFO data.

Parameters

[in]	FileHandle	The file handle whose size is to be changed.
[in]	Size	The new size.

Return values

EFI_SUCCESS	The operation completed successfully.
EFI_DEVICE_ERROR	Cannot access the file.
EFI_INVALID_PARAMETER	FileHandle is NULL.

EFI_STATUS EFIAPI FileHandleWrite	(	IN EFI_FILE_HANDLE	FileHandle,
		IN OUT UINTN *	BufferSize,
		IN VOID *	Buffer
	)

Write data to a file.

This function writes the specified number of bytes to the file at the current file position. The current file position is advanced the actual number of bytes written, which is returned in BufferSize. Partial writes only occur when there has been a data error during the write attempt (such as "volume space full"). The file is automatically grown to hold the data if required. Direct writes to opened directories are not supported.

Parameters

[in]	FileHandle	The opened file for writing.
[in,out]	BufferSize	On input, the number of bytes in Buffer. On output, the number of bytes written.
[in]	Buffer	The buffer containing data to write is stored.

Return values

EFI_SUCCESS	Data was written.
EFI_UNSUPPORTED	Writes to an open directory are not supported.
EFI_NO_MEDIA	The device has no media.
EFI_DEVICE_ERROR	The device reported an error.
EFI_VOLUME_CORRUPTED	The file system structures are corrupted.
EFI_WRITE_PROTECTED	The device is write-protected.
EFI_ACCESS_DENIED	The file was opened for read only.
EFI_VOLUME_FULL	The volume is full.

EFI_STATUS EFIAPI FileHandleWriteLine	(	IN EFI_FILE_HANDLE	Handle,
		IN CHAR16 *	Buffer
	)

Function to write a line of text to a file.

If the file is a Unicode file (with UNICODE file tag) then write the unicode text. If the file is an ASCII file then write the ASCII text. If the size of file is zero (without file tag at the beginning) then write ASCII text as default.

Parameters

[in]	Handle	FileHandle to write to.
[in]	Buffer	Buffer to write, if NULL the function will take no action and return EFI_SUCCESS.

Return values

EFI_SUCCESS	The data was written. Buffer is NULL.
EFI_INVALID_PARAMETER	Handle is NULL.
EFI_OUT_OF_RESOURCES	Unable to allocate temporary space for ASCII string due to out of resources.

See Also: FileHandleWrite

Variable Documentation

CONST UINT16 gUnicodeFileTag

The tag for use in identifying UNICODE files. If the file is UNICODE, the first 16 bits of the file will equal this value.

Functions

Variables

Detailed Description

Function Documentation

Variable Documentation