Intel Extensible Firmware Interface, Спецификация

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Extensible Firmware Interface Specification
70 12/12/00 Version 1.02
Description
The
LoadImage()
function loads an EFI image into memory and returns a handle to the image.
The image is loaded in one of two ways. If
SourceBuffer
is not
NULL
, the function is a
memory-to-memory load in which
SourceBuffer
points to the image to be loaded and
SourceSize
indicates the image’s size in bytes. In this case, the caller has copied the image into
SourceBuffer
and can free the buffer once loading is complete.
If
SourceBuffer
is
NULL
, the function is a file copy operation that uses the
SIMPLE_FILE_SYSTEM
protocol and then the
LOAD_FILE
protocol on the
DeviceHandle
to
access the file referred to by
FilePath
. In this case, the
BootPolicy
flag is passed to the
LOAD_FILE.LoadFile()
function and is used to load the default image responsible for booting
when the
FilePath
only indicates the device. For more information see the discussion of the
Load File Protocol in Chapter 11.
Regardless of the type of load (memory-to-memory or file copy), the function relocates the code in
the image while loading it.
Once the image is loaded, firmware creates and returns an
EFI_HANDLE
that identifies the image
and supports the
LOADED_IMAGE
protocol. The caller may fill in the image’s “load options” data,
or add additional protocol support to the handle before passing control to the newly loaded image
by calling
StartImage()
. Also, once the image is loaded, the caller either starts it by calling
StartImage()
or unloads it by calling
Unload()
.
Status Codes Returned
EFI_SUCCESS Image was loaded into memory correctly.
EFI_NOT_FOUND
The FilePath was not found.
EFI_INVALID_PARAMETER One of the parameters has an invalid value.
EFI_UNSUPPORTED The image type is not supported, or the device path can not be
parsed to locate the proper protocol for loading the the file.
EFI_OUT_OF_RESOURCES Image was not loaded due to insufficient resources.
EFI_LOAD_ERROR Image was not loaded because the image format was corrupt or not
understood.
EFI_DEVICE_ERROR Image was not loaded because the device returned a read error.