Smooth graphics mode transition from GRUB to kernel

Matthew Garrett mjg59 at
Mon Aug 10 11:12:48 UTC 2009

On Mon, Aug 10, 2009 at 11:31:13AM +0100, Colin Watson wrote:

> This doesn't seem like it ought to be an inherent limitation; several
> architectures start up with nothing but a framebuffer, after all. I'm
> wondering if we're just not programming the boot parameter structure
> quite right in GRUB, or perhaps if there's some configuration tweak that
> the kernel needs to support this. Can anyone see anything wrong with the
> attached patch when applied to the current grub2 package in Karmic?
> loader/i386/linux.c is the key file.

KMS-based framebuffers are accelerated and may set up stuff like tiling, 
so you don't necessarily have a nice, easy linear framebuffer. Grub will 
have programmed a vesa mode which *is* a nice, easy linear framebuffer - 
but you'd then need to bind vesafb to it right at the start of kernel 
boot and swap from that to the native driver. It's not actually a 
terribly easy problem.

Matthew Garrett | mjg59 at

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