Is it necessary to have CyanogenMod/LineageOS Port for successful Sailfish OS port? [answered]

SailfishOS, like Android, are a blend of Linux.

The Linux Kernel needs the specific drivers to work, otherwise you won't be able to boot or use certain features (sound, graphics, wlan, mobile... to point out some import ones) The terms of the GPL dictate that every vendor needs to make the Kernel Source for their mobiles available. The same is not true for drivers linked against the kernel, e.g. your chipset, they stay closed source due to Copyright and are not available to the general public.

If you want to run another Operating System on your phone, you need the Sourcecode of the OS as well as drivers for your hardware. Acquiring the drivers can be somewhat tricky (e.g. mostly for Mediatek Chipsets) or rather straightforward (Qualcomm mostly). The Lineage Guys and Girls have taken care of that for their supported devices.

The Community Ports somewhat depend on that work during the build process.

If there is no Port, you need to acquire the drivers, correct kenel, fixes and Co. yourself.

Thanks a lot @vorletzter & @Sthocs.