FdtDump will dump the device tree blob to the same volume the tool is located on. This is sometimes useful, but keep in mind that some UEFI implementations can patch the DTB on the way out during ExitBootServices, meaning you might not get the same (correct) data if you dumped the DTB from the OS proper.
Note: this tool is not available for IA32, X64, IPF and EBC targets.
An optional parameter specifies the path, relative to the volume root, where to place the tables. E.g.:
fs16:> FdtDump.efi
fs16:> FdtDump.efi MyFunkySystem