yast2-tftp-server from YaST:Head:installer project
Select Your Operating System
Add repository and install manually
For openSUSE 13.1 run the following as root:
zypper addrepo https://download.opensuse.org/repositories/YaST:Head:installer/openSUSE_13.1/YaST:Head:installer.repo zypper refresh zypper install yast2-tftp-server