Data Structures
struct	EFI_OPEN_FILE
	Public information about the open file. More...

Macros
#define	MAX_PATHNAME 0x200

Enumerations
enum	EFI_OPEN_FILE_TYPE { EfiOpenLoadFile, EfiOpenMemoryBuffer, EfiOpenFirmwareVolume, EfiOpenFileSystem, EfiOpenBlockIo, EfiOpenTftp, EfiOpenMaxValue }
	Type of the file that has been opened. More...

enum	EFI_SEEK_TYPE { EfiSeekStart, EfiSeekCurrent, EfiSeekEnd, EfiSeekMax }
	Type of Seek to perform. More...

Functions
EFI_OPEN_FILE *	EfiOpen (IN CHAR8 *PathName, IN CONST UINT64 OpenMode, IN CONST EFI_SECTION_TYPE SectionType)

EFI_STATUS	EfiCopyFile (IN CHAR8 DestinationFile, IN CHAR8 SourceFile)

EFI_OPEN_FILE *	EfiDeviceOpenByType (IN EFI_OPEN_FILE_TYPE DeviceType, IN UINTN Index)

EFI_STATUS	EfiClose (IN EFI_OPEN_FILE *Stream)

UINTN	EfiTell (IN EFI_OPEN_FILE Stream, OUT UINT64 CurrentPosition)

EFI_STATUS	EfiSeek (IN EFI_OPEN_FILE *Stream, IN EFI_LBA Offset, IN EFI_SEEK_TYPE SeekType)

EFI_STATUS	EfiRead (IN EFI_OPEN_FILE Stream, OUT VOID Buffer, OUT UINTN *BufferSize)

EFI_STATUS	EfiReadAllocatePool (IN EFI_OPEN_FILE Stream, OUT VOID Buffer, OUT UINTN BufferSize)

EFI_STATUS	EfiWrite (IN EFI_OPEN_FILE Stream, OUT VOID Buffer, OUT UINTN *BufferSize)

UINTN	EfiGetDeviceCounts (IN EFI_OPEN_FILE_TYPE Type)

EFI_STATUS	EfiSetCwd (IN CHAR8 *Cwd)

CHAR8 *	EfiGetCwd (VOID)

Detailed Description

Library functions that perform file IO. Memory buffer, file system, and firmware volume operations are supported.

SPDX-License-Identifier: BSD-2-Clause-Patent

Basic support for opening files on different device types. The device string is in the form of DevType:Path. Current DevType is required as there is no current mounted device concept of current working directory concept implement by this library.

Device names are case insensitive and only check the leading characters for unique matches. Thus the following are all the same: LoadFile0: l0: L0: Lo0:

Supported Device Names: A0x1234:0x12 - A memory buffer starting at address 0x1234 for 0x12 bytes l1: - EFI LoadFile device one. B0: - EFI BlockIo zero. fs3: - EFI Simple File System device 3 Fv2: - EFI Firmware Volume device 2 1.2.3.4:name - TFTP IP and file name

Macro Definition Documentation

#define MAX_PATHNAME 0x200

Enumeration Type Documentation

enum EFI_OPEN_FILE_TYPE

Type of the file that has been opened.

Enumerator
EfiOpenLoadFile
EfiOpenMemoryBuffer
EfiOpenFirmwareVolume
EfiOpenFileSystem
EfiOpenBlockIo
EfiOpenTftp
EfiOpenMaxValue

enum EFI_SEEK_TYPE

Type of Seek to perform.

Enumerator
EfiSeekStart
EfiSeekCurrent
EfiSeekEnd
EfiSeekMax

Function Documentation

EFI_STATUS EfiClose ( IN EFI_OPEN_FILE * Stream )

Close a file handle opened by EfiOpen() and free all resources allocated by EfiOpen().

Parameters

Stream Open File Handle

Returns: EFI_INVALID_PARAMETER Stream is not an Open File; EFI_SUCCESS Steam closed

EFI_STATUS EfiCopyFile	(	IN CHAR8 *	DestinationFile,
		IN CHAR8 *	SourceFile
	)

EFI_OPEN_FILE* EfiDeviceOpenByType	(	IN EFI_OPEN_FILE_TYPE	DeviceType,
		IN UINTN	Index
	)

Use DeviceType and Index to form a valid PathName and try and open it.

Parameters

DeviceType	Device type to open
Index	Device Index to use. Zero relative.

Returns: NULL Open failed; Valid EFI_OPEN_FILE handle

CHAR8* EfiGetCwd ( VOID )

Set the Current Working Directory (CWD). If a call is made to EfiOpen () and the path does not contain a device name, The CWD is prepended to the path.

Parameters

Cwd	Current Working Directory

Returns: NULL No CWD set; 'other' malloc'ed buffer contains CWD.

UINTN EfiGetDeviceCounts ( IN EFI_OPEN_FILE_TYPE Type )

Return the number of devices of the current type active in the system

Parameters

Type	Device type to check

Returns: 0 Invalid type

EFI_OPEN_FILE* EfiOpen	(	IN CHAR8 *	PathName,
		IN CONST UINT64	OpenMode,
		IN CONST EFI_SECTION_TYPE	SectionType
	)

Open a device named by PathName. The PathName includes a device name and path separated by a :. See file header for more details on the PathName syntax. There is no checking to prevent a file from being opened more than one type.

SectionType is only used to open an FV. Each file in an FV contains multiple sections and only the SectionType section is opened.

For any file that is opened with EfiOpen() must be closed with EfiClose().

Parameters

PathName	Path to parse to open
OpenMode	Same as EFI_FILE.Open()
SectionType	Section in FV to open.

Returns: NULL Open failed; Valid EFI_OPEN_FILE handle

EFI_STATUS EfiRead	(	IN EFI_OPEN_FILE *	Stream,
		OUT VOID *	Buffer,
		OUT UINTN *	BufferSize
	)

Read BufferSize bytes from the current location in the file. For load file and FV case you must read the entire file.

Parameters

Stream	Open File Handle
Buffer	Caller allocated buffer.
BufferSize	Size of buffer in bytes.

Returns: EFI_SUCCESS Stream is not an Open File; EFI_END_OF_FILE Tried to read past the end of the file; EFI_INVALID_PARAMETER Stream is not an open file handle; EFI_BUFFER_TOO_SMALL Buffer is not big enough to do the read; "other" Error returned from device read

EFI_STATUS EfiReadAllocatePool	(	IN EFI_OPEN_FILE *	Stream,
		OUT VOID **	Buffer,
		OUT UINTN *	BufferSize
	)

Read the entire file into a buffer. This routine allocates the buffer and returns it to the user full of the read data.

This is very useful for load file where it's hard to know how big the buffer must be.

Parameters

Stream	Open File Handle
Buffer	Pointer to buffer to return.
BufferSize	Pointer to Size of buffer return..

Returns: EFI_SUCCESS Stream is not an Open File; EFI_END_OF_FILE Tried to read past the end of the file; EFI_INVALID_PARAMETER Stream is not an open file handle; EFI_BUFFER_TOO_SMALL Buffer is not big enough to do the read; "other" Error returned from device read

EFI_STATUS EfiSeek	(	IN EFI_OPEN_FILE *	Stream,
		IN EFI_LBA	Offset,
		IN EFI_SEEK_TYPE	SeekType
	)

Seek to the Offset location in the file. LoadFile and FV device types do not support EfiSeek(). It is not possible to grow the file size using EfiSeek().

SeekType defines how use Offset to calculate the new file position: EfiSeekStart : Position = Offset EfiSeekCurrent: Position is Offset bytes from the current position EfiSeekEnd : Only supported if Offset is zero to seek to end of file.

Parameters

Stream	Open File Handle
Offset	Offset to seek too.
SeekType	Type of seek to perform

Returns: EFI_INVALID_PARAMETER Stream is not an Open File; EFI_UNSUPPORTED LoadFile and FV does not support Seek; EFI_NOT_FOUND Seek past the end of the file.; EFI_SUCCESS Steam closed

EFI_STATUS EfiSetCwd ( IN CHAR8 * Cwd )

Set the Current Working Directory (CWD). If a call is made to EfiOpen () and the path does not contain a device name, The CWD is prepended to the path.

Parameters

Cwd	Current Working Directory to set

Returns: EFI_SUCCESS CWD is set; EFI_INVALID_PARAMETER Cwd is not a valid device:path

UINTN EfiTell	(	IN EFI_OPEN_FILE *	Stream,
		OUT UINT64 *	CurrentPosition
	)

Return the size of the file represented by Stream. Also return the current Seek position. Opening a file will enable a valid file size to be returned. LoadFile is an exception as a load file size is set to zero.

Parameters

Stream Open File Handle

Returns: 0 Stream is not an Open File or a valid LoadFile handle

EFI_STATUS EfiWrite	(	IN EFI_OPEN_FILE *	Stream,
		OUT VOID *	Buffer,
		OUT UINTN *	BufferSize
	)

Write data back to the file.

Parameters

Stream	Open File Handle
Buffer	Pointer to buffer to return.
BufferSize	Pointer to Size of buffer return..

Returns: EFI_SUCCESS Stream is not an Open File; EFI_END_OF_FILE Tried to read past the end of the file; EFI_INVALID_PARAMETER Stream is not an open file handle; EFI_BUFFER_TOO_SMALL Buffer is not big enough to do the read; "other" Error returned from device write

Data Structures

Macros

Enumerations

Functions

Detailed Description

Macro Definition Documentation

Enumeration Type Documentation

Function Documentation