[coreboot] kexec --reset-vga from an inteldrmfb frame buffer

[Trammell Hudson]

When I have my coreboot payload Linux kernel setup a console framebuffer
and then kexec into Xen + another kernel, the video glitches out quite
a bit before falling back to text mode.  The kexec --reset-vga option
doesn't seem to have any effect.

I read in the docs that kexec and framebuffers don't get along and
it seems that the patch from 2006 only works with VESA:

https://lkml.org/lkml/2006/7/17/58

My system is using i915 graphics, and there is no option ROM, so I don't
think it even shows up with any VESA compatible modes.  Is there any
way to reset the card or to transfer the mode info to the next kernel?