Support for Bipac 7800NXL router


Thank you for the amazing project!
I have a router where I would like to install OpenWRT to serve as a local 'always-on' L2TP/IPsec client and router locally.
The support table shows that 7800N router supported and trying that image tells that "The selected file contains an illegal image"
Is it worth pursuing with installation of OpenWRT on the device? If so, what are my options, please?

I am ok with loosing it's 'adsl modem' functionality