The mainline rootfs is for devices which use upstream Linux kernel with open source drivers on standard GNU ABI, rather than Android. So, for PinePhone/Librem 5/RPi.
The hybris rootfs is for devices which require Android kernel and its bionic ABI (hybris is for binding to the Android HAL from within Linux).
If you're porting a device, you almost certainly need the hybris version.
@YamiYukiSenpai that room is still listed in Halium official documentation (http://docs.halium.org/en/latest/porting/first-steps.html?highlight=%23halium%3Adisroot.org) but maybe they've a problem with federation and that's why you can't access it from your instance?
No one responded, so I figured I'd shine some light here. @walidham, Your port is built for armhf. You need to build for arm64 on the V20, we're not ARMv7, we're ARMv8.
So when building, you'd likely use ARCH=aarch64 instead of ARCH=armhf, if you made the device tree yourself, you may have other things that need done in the kernel's configuration.
@tigerpro Nice! So I have to be more careful when tweaking with Halium then.
I'll update when I can when Halium is running on my laptop.
I finally saw the word GIT in the apt install, so I guess I see where "build" is going
@RoyD the current effort to port Halium / UT to BQ devices are only on these models, at least for now: https://github.com/Halium/projectmanagement/issues?utf8=✓&q=is%3Aissue+is%3Aopen+bq
Maybe you can ask https://aquaris-dev.org/ if there's any chance to port LineageOS to U2