windows/ubuntu dual boot

[Jeffrey Walton]

On Tue, Aug 20, 2024 at 3:19 PM bruce <badouglas at gmail.com> wrote:
>
> Got an old windows laptop.It has/had ubuntu as dual boot. At one time,
> I know it had the ability to see the screen when logging on, to select
> the OS. This no longer happens.
>
> Any one know what might be happening, or what I can check?

You are light on details, so this is just speculation... The old
signatures are invalid due to grub and shim bugs. See
<https://ubuntu.com/blog/mitigating-boothole-theres-a-hole-in-the-boot-cve-2020-10713-and-related-vulnerabilities>
for more details.

Jeff