Intel Extensible Firmware Interface - Manual (Page 362)

Extensible Firmware Interface Specification
11-2 12/01/02 Version 1.10
LOAD_FILE.LoadFile()
Summary
Causes the driver to load a specified file.
Prototype
EFI_STATUS
(EFIAPI *EFI_LOAD_FILE) (
IN EFI_LOAD_FILE_INTERFACE *This,
IN EFI_DEVICE_PATH *FilePath,
IN BOOLEAN BootPolicy,
IN OUT UINTN *BufferSize,
IN VOID *Buffer OPTIONAL
);
Parameters
This Indicates a pointer to the calling context. Type
EFI_LOAD_FILE_INTERFACE is defined in Section 11.1.
FilePath The device specific path of the file to load. Type EFI_DEVICE_PATH
is defined in Chapter 8.
BootPolicy If TRUE , indicates that the request originates from the boot manager, and
that the boot manager is attempting to load FilePath as a boot
selection. If FALSE , then FilePath must match an exact file to be
loaded.
BufferSize On input the size of Buffer in bytes. On output with a return code of
EFI_SUCCESS , the amount of data transferred to Buffer .
On output with a return code of EFI_BUFFER_TOO_SMALL , the size
of Buffer required to retrieve the requested file.
Buffer The memory buffer to transfer the file to. If Buffer is NULL , then no
the size of the requested file is returned in BufferSize .
Description
The LoadFile() function interprets the device-specific FilePath parameter, returns the entire
file into Buffer , and sets BufferSize to the amount of data returned. If Buffer is NULL ,
then the size of the file is returned in BufferSize . If Buffer is not NULL , and BufferSize
is not large enough to hold the entire file, then EFI_BUFFER_TOO_SMALL is returned, and
BufferSize is updated to indicate the size of the buffer needed to obtain the file. In this case, no
data is returned in Buffer .
If BootPolicy is FALSE the FilePath must match an exact file to be loaded. If no such file
exists, EFI_NOT_FOUND is returned. If BootPolicy is FALSE , and an attempt is being made
to perform a network boot through the PXE Base Code protocol, EFI_UNSUPPORTED is returned.