There is no mainline kernel SFOS version without all the libhybris yet and probably won't be any time soon. Sure it's possible to make but Jolla has no resources for it. Many of the functionality in SFOS still depend highly on libhybris and for a good reason, they work well so why reinvent the wheel. I do hope that some day SFOS will have it's own drivers all the way and Google Android would have to lick their wounds :P