I've seen this on a sandybridge machine booting 3.7 kernel from Fedora 18.
A previous 3.6.9 based kernel doesn't show it.
The VGA mode screen appears to get trampled before the graphics driver screen loads.
I think booting with quiet makes it more apparant.
fbcon transition, so I feel safe by hiding amongst the team...
P.S. Ben says he saw it. Tag.
So we splatter the screen full with funny characters before setting up the kms screen ... that's new ;-) No idea what's going on here.
Wanted to add a nugget from some IRC discussion: currently scrutinizing Fedora patches around kernel v3.6.9 .
I'm having a hard time reproducing with Arch's 3.6.11 kernel. As in, haven't seen the visual corruption yet at the specified point.
okay this is wierd I can make it happen with nomodeset quiet so I think i915 is off the hook!
Though this means its either a wierd BIOS thing, or a wierd race, since I haven't seen it reported on older hw or anything non-intel.
Since then, Dave worked out that it was mishandling of the "intensity" bit in the VT emulation: https://patchwork.kernel.org/patch/2038031/