Efi_file.setposition(), Setposition(), Func – Intel Extensible Firmware Interface User Manual
Page 388

Extensible Firmware Interface Specification
11-28
12/01/02
Version 1.10
EFI_FILE.SetPosition()
Summary
Sets a file’s current position.
Prototype
EFI_STATUS
(EFIAPI *EFI_FILE_SET_POSITION) (
IN
EFI_FILE
*This,
IN
UINT64
Position
);
Parameters
This
A pointer to the
instance that is the he file handle to set the
requested position on. See the type
EFI_FILE
protocol description.
Position
The byte position from the start of the file to set.
Description
The
SetPosition()
function sets the current file position for the handle to the position
supplied. With the exception of seeking to position 0xFFFFFFFFFFFFFFFF, only absolute
positioning is supported, and seeking past the end of the file is allowed (a subsequent write would
grow the file). Seeking to position 0xFFFFFFFFFFFFFFFF causes the current position to be set to
the end of the file.
If
This
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.
Status Codes Returned
EFI_SUCCESS
The position was set.
EFI_UNSUPPORTED
The seek request for nonzero is not valid on open
directories.