--tftp-root=<directory>[,<interface>]
Look for files to transfer using TFTP relative to the given directory. When this is set, TFTP paths which include ".." are rejected, to stop clients getting outside the specified root. Absolute paths (starting with /) are allowed, but they must be within the tftp-root. If the optional interface argument is given, the directory is only used for TFTP requests via that interface.