Comment 19 for bug 1016170

On Wed, Jun 27, 2012 at 09:23:39PM -0000, Barry Warsaw wrote:
> On Jun 27, 2012, at 08:22 PM, Joseph Salisbury wrote:

> >Barry, there are some additional things that can be done to gather further
> >debug information. Details can be found at:
> >https://wiki.ubuntu.com/DebuggingKernelBoot

> It seems like the problem is in the handoff from refit to grub, since I cannot
> get to a grub screen by holding down the shift when the machine is in "I want
> to hang" mode. No shift is necessary after the failed boot because the grub
> screen automatically comes up, and when it does, it will always boot.

> So I'm not sure the recommendations on that wiki page are useful, since they
> all assume you can get to the grub screen.

Note that holding down the shift key to get to the grub screen assumes a
BIOS that will handle the shift key. I have no idea if this works at all in
an EFI environment.

You can force the grub menu to always be shown, with or without a previous
failure and with or without a shift key, by setting GRUB_TIMEOUT=-1 (I
think).