i was trying to comment on the idea that something being open source doesn't change that it needs compiling for a particular platform, and that it should be expected to not be straightfowards. especially at the low level where you need to raise interrupts and fill particular registers...
Oh that's actually reasonably cross platform these days. You can write drivers that are ISA independent and make use of kernel APIs for interacting with the hardware. There's no reason to drop into assembly. (Although yes sometimes the memory coherency model or details of the interrupt handler protocol bleed into a driver requiring tweaks to get it to work, but those are bugs a good driver author can avoid.)
some hardware can be a nightmare for this stuff though...
i still contend that it can be much more complicated than simply recompiling for your target... and even when its not, that is still one more step than doing nothing, which was the impression i got from the "its open source you can do nothing" comment.