| #
300780 |
|
26-May-2016 |
jhb |
Add some routines for working with EFI DEVICE_PATH objects.
- efi_lookup_devpath() uses the DEVICE_PATH_PROTOCOL to obtain the
DEVICE_PATH for a given EFI handle.
- efi_lookup_image_devpath() uses the LOADED_IMAGE_DEVICE_PATH_PROTOCOL
to lookup the device path of the device used to load a loaded image.
- efi_devpath_name() uses the DEVICE_PATH_TO_TEXT_PROTOCOL to generate
a string description of a device path. The returned string is a CHAR16
string that can be printed via the recently added '%S' format in
libstand's printf(). Note that the returned string is returned in
allocated storage that should be freed by calling
efi_free_devpath_name().
- efi_devpath_last_node() walks a DEVICE_PATH returning a pointer to the
final node in the path (not counting the terminating node). That is,
it returns a pointer to the last meaninful node in a DEVICE_PATH.
- efi_devpath_trim() generates a new DEVICE_PATH from an existing
DEVICE_PATH. The new DEVICE_PATH does not include the last
non-terminating node in the original path. If the original DEVICE_PATH
only contains the terminating node, this function returns NULL.
The caller is responsible for freeing the returned DEVICE_PATH via
free().
- efi_devpath_handle() attempts to find a handle that corresponds to a
given device path. However, if nodes at the end of the device path do
not have valid handles associated with them, this function will return
a handle that matches a node earlier in the device path. In particular,
this function returns a handle for the node closest to the end of the
device path which has a valid handle.
Sponsored by: Cisco Systems
|