[efi] Make EFI_DEVICE_PATH_TO_TEXT_PROTOCOL optional
Some UEFI systems (observed with a Mac Pro) do not provide
EFI_DEVICE_PATH_TO_TEXT_PROTOCOL. Since we use this protocol only for
debug messages, make it optional and fall back to printing the raw
device path bytes.
Reported-by: Matt Woodward <pxematt@woodwardcc.com>
Tested-by: Matt Woodward <pxematt@woodwardcc.com>
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Exploit the redefinition of iPXE error codes to include a "platform
error code" to allow for meaningful conversion of EFI_STATUS values to
iPXE errors and vice versa.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
Michael Brown