odd behaviour with graphics, vt(4), VGA, and probing the text region leading to NMIs at boot

[Adrian Chadd]

On 3 January 2015 at 09:31, Alfred Perlstein <bright at mu.org> wrote:
> Sounds like the virtualization code is sensitive to the mode.  Meaning that whatever is virtualizing the graphics card doesn't do the proper thing when you're in a graphical mode.  Can't the probes be turned off?

So it's happening quite late in the boot process - when the ISA bus is
being probed. So, maybe we can just avoid probing the dev/vga stuff
like this.

I'll have to talk to Ed/ray about how the syscons and vt devices hold
together. I'm kinda shocked that we're re-probing things via an ISA
probe so late in the boot process.

> Basically when the "card" is in gfx mode, it doesn't do the right thing for those memory addresses.  Sounds like the fix would be to not touch those regions unless you're actually in text mode.




-adrian