Ah yes, mainline support was the more condensed description I was after! That is indeed where it's at; if you are stuck with out-of-tree or vendor binary-only d

Ah yes, mainline support was the more condensed description I was after! That is indeed where it's at; if you are stuck with out-of-tree or vendor binary-only distribution, you're screwed. It can be a bit of a hassle if all you have is something like "926EJS" as supported core instead of the SoC name "F1C100s", but either way, browse the linux kernel for support for your SoC to at least get a feel for its support status. If a (compiled) device tree for the SBC is available and the bootrom is either super small or open/free/libre, you can expect good integration and long life out of the device. Even in the worst case you'll be able to follow generic buildroot or yocto instructions to get it running with up-to-date software.