efivar_device_path_to_unix_path translates from UEFI to Unix
efivar_unix_path_to_device_path translates from Unix to UEFI
At present, only HD() device types are supported (both GPT and
MBR). CdRom and floppy devices aren't supported. ZFS isn't supported
because there's no way in the UEFI standard to specify a ZFS datastore.
Network devices aren't supported either.
Three forms of Unix path are accepted: /path/to/file (for a mounted
filesystem), //path/to/file (uses the EFI partition on the same disk
as /), and dev:/path/to/file (for unmounted filesystem). Two forms are
produced (the first and last).
Sponsored by: Netflix
efidp_size will return the size, in bytes, of a EFI device path
structure. This is a convenience wrapper in the same style as the
other linux routines. It's implemented by GetDevicePathSize from EDK2
we already needed for other things.
Sponsored by: Netflix
This commit implements the (mostly?) Linux compatible
efidp_format_device_path and efidp_parse_device_path APIs. These are
the only APIs exposed through this library. However, they are built on
code from Tianocore's EDK2 MdePkg. They are brought in as new files
here for reasons described in FreeBSD-update.
Symbol versioning will be introduced to control what's exported from
the EDK2 code.
Some structural changes may be necessary when we move to sharing with
sys/boot/efi.
Sponsored by: Netflix
