The use of tftp does not require an account or password on the remote system. Due to the lack of authentication information, tftp will allow only publicly readable files to be accessed. Files may be written only if they already exist and are publicly writable. Note that this extends the concept of ``public'' to include all users on all hosts that can be reached through the network; this may not be appropriate on all systems, and its implications should be considered before enabling this service.
By default, the entry for tftpd in /etc/inetd.conf is commented out. To make tftpd operational, the comment character(s) must be deleted from the tftpd entry. See inetd.conf(4tcp) for details.
Before responding to a request, the server attempts to change its current directory to homedir; the default value is /tftpboot.
RFC 783