Taken from http://www.davidsudjiman.info/?p=93.

1. Install tftpd and related packages.

$ sudo apt-get install xinetd tftpd tftp

2. Create /etc/xinetd.d/tftp and put this entry:

service tftp
{
protocol        = udp
port            = 69
socket_type     = dgram
wait            = yes
user            = nobody
server          = /usr/sbin/in.tftpd
server_args     = -s /tftpboot
disable         = no
}

3. Make /tftpboot directory

$ sudo mkdir /tftpboot
$ sudo chmod -R 777 /tftpboot
$ sudo chown -R nobody /tftpboot

4. Start tftpd through xinetd

$ sudo /etc/init.d/xinetd start

5. Testing. Tranfering file hda.txt from 192.168.1.100 (Client using tftp) to 192.168.1.100 (Server 192.168.1.100). Get an example file to transfer (eg. hda.txt)

$ touch /tftpboot/hda.txt
$ chmod 777 /tftpboot/hda.txt
$ ls -l /tftpboot/
total 0
-rwxrwxrwx  1 davids davids 0 2006-03-27 23:04 hda.txt
$ tftp 192.168.1.100
tftp> put hda.txt
Sent 722 bytes in 0.0 seconds
tftp> quit
$ ls -l /tftpboot/
total 4
-rwxrwxrwx  1 davids davids 707 2006-03-27 23:07 hda.txt