Compile tun.ko and unionfs.ko under Prestigio PMP5080

Question

Android

Good day.
I want to install OpenVPN on this device, which is why tun.ko and unionfs.ko are needed. On the Internet, I did not find them ready for the Prestigio PMP5080.
Ruth is available. SDK found

With Linux, in general, I'm on friendly terms, but here I don't know what and how to do. Please describe in detail how I can compile these binaries for myself.
Thanks in advance.