Tftp

To enable tftp on your Centos server perform the following as root:

$ yum install tftp*
$ chmod 777 /tftpboot
$ vi /etc/xinetd.d/tftp ## Change disable = yes to disable = no
$ /sbin/restorecon -r /tftpboot
$ system-config-securitylevel-tui ## add tftp:udp in the customize menu for other ports
$ service network restart
$ service xinetd restart
$ echo "test">/tftpboot/test
$ tftp localhost ## command: get test

check that the file test is received locally.

Unfortunately we cannot test this from bren because the tftp implementation are using random selected ports.

+-------------+                        +--------------+
|             |                        |              |
|             | port xx                |              |
|   bren      |----------------------->| devhost      |
|             |            port 69/udp |              |
|             |                        |              |
+-------------+                        +--------------+

+-------------+                        +--------------+
|             |                        |              |
|             |            port xx     |              |
|   bren      |<-----------------------| devhost      |
|             | port nn                |              |
|             |                        |              |
+-------------+                        +--------------+
where nn is randomly selected and with almost 100% certainty not open in the bren firewall. 
(Remember: The source port (xx) does not cause any problems.)

If you have a PC with fully open firewall you can test the setup - maybe momentary switch off your firewall for the test - provided you have a tftp client installed on your PC.

The EA 2478 board will work under these conditions, because uBoot accepts incoming tftp traffic on any port.