Re: Laptop powerdown when early boot incl. bootloader phase stuck (Was: Bug 1742953 - No Screensaver/Powerdown after Inactivity at LUKS Password Prompt)
On Fri, Aug 23, 2019 at 5:48 AM Jan Pokorný <jpokorny(a)redhat.com> wrote:
One such other situation is having the bootloader (grub2) failed and
hence be stuck in 'press a key to continue' or just staying in the
selection menu without any timeout ticking for whatever reason.
There is signature verification of all the bootloader binaries, and
the kernel, in the UEFI Secure Boot case. I'm not sure what kind of
signature checking could be enabled in the case of UEFI Secure Boot
disable and BIOS and other firmware types. First, there'd need to be
some way to identify an error, then what can be done (try another
kernel, OK what if that fails?) to mitigate it.
Since Fedora 30, the grub.cfg is no longer modified by grubby, it's a
static configuration file. So at least in the normal case, it's
created correctly from the outset and other than bit rot it should
always be present and correct forever. What if any of that changes?
I'm not sure what the fallback behavior is, it's possibly worth
exploring. The Fedora GRUB BLS module does have some sanity testing of
the BLS snippet in it, but I'm not sure how robust it is and if
there's a fallback other than trying another menu entry, which means
trying another kernel. At the point which it's exhausted all menu
entries and kernels, then what? Does GRUB in the pre-boot environment
on all archs have the capacity to power off the system? I'm not sure.
It's an interesting question.
--
Chris Murphy