Following is the procedure which will guide you for setting up the Linux PC as a tftp server. This is mostly required so that you can download some images from this server to your tftp client.
On Ubuntu Linux
sudo apt-get install tftpd-hpa
sudo apt-get install tftp
sudo service tftpd-hpa start
Above steps will install tftp server, creates directory /srv/tftp on Ubuntu 20.04 and start the tftp server, which you can check using below command,
$ ps -ax | grep tftp 32850 ? Ss 0:00 /usr/sbin/in.tftpd --listen --user tftp --address :69 --secure /srv/tftp
On other Ubuntu versions, you may see tftp server started with directory /var/lib/tftpboot
One we have setup, tftpserver now we will need to copy images which we want to flash on the target.
$ sudo cp -r FOLDER_WITH_FILES/* /var/lib/tftpboot