Hello, On Wed, 23 Apr 2014 23:41:33 +0100 David Brownlee <[email protected]> wrote:
> My question was more "why does NetBSD try to attach tcx0 on a machine > with serial console and genfb on the same machine with graphical > console (albeit an emulated qemu machine). Should it not be trying to > attach tcx in box cases? Because tcx was never updated to return a match score higher than 1. I'll fix that in a minute. Frankly I'm surprised that people actually use genfb at sbus, given its lack of colour map control ( thanks to OBP < 3 not having a standard method to do it... ) ;) > >> >> So an immediate workaround to enable running NetBSD-6.x would be to > >> >> update to qemu-2.0.0 and use "-vga cg3", meanwhile someone can have a > >> >> poke at NetBSD and see why -nographic and emulated tcx have issues... > >> >> :) > >> > > >> > See above. A proper workaround would be to either add the missing bits > >> > to qemu or find a way for our tcx driver to detect qemu and skip the > >> > hardware that's not actually emulated. > >> > >> Would the output of "ofctl -p" give any clues (attached). This is from > >> a "not -nographic" run from a HEAD kernel. > > > > Actually the diff between "-nographics" and "not -nographics" would be more > > interesting. > > That we can do. The "-nographics" case is with a kernel compiled without tcx0: > - http://sync.absd.org/sparc/qemu-ofctl-nographic.txt > - http://sync.absd.org/sparc/qemu-ofctl.txt > > Thats... clever - the only difference to the tcx properties in the > -nographics case is that it is missing 'address' And that matches real OBP / OF - no need for the firmware to map the framebuffer if it isn't going to scribble into it. So qemu doesn't emulate a complete tcx in the -nographics case but it doesn't really tell us. As a workaround I could check for /packages/grubfs-files and skip tcx if that node is present and tcx isn't the console. Looks more like a bug in qemu though. have fun Michael
