Re: Grub behaving differently when non-UEFI boot options are enabled

[Randy Goldenberg]

On Tuesday July 31, 2018, Yann SALMON wrote: 

> Hello,
>
> The main hard disk of my Dell Precision 3620 is partitioned with a GPT
> and Ubuntu is installed and boots (via grub2) in UEFI mode.
>
> What I recently discovered is that the early initialisation of the
> graphics card seems to happen differently when the "Enable legacy boot
> options" option is activated in the BIOS. Notably, the apparent screen
> resolution is not the same.
>
> This is of interest to me because I have difficulties with the Nvidia
> driver crashing (after boot) when switching VT (only when legacy boot
> options are not enabled).
>
> The question : what sense does it make that this BIOS setting influences
> the graphics card so much, considering we are booting an UEFI entry in
> each case ? Is this a bug in the Dell BIOS, in grub, in the nvidia
> driver ? How can I investigate this ?

In my experience, the driver does not crash when switching VTs.  VTs are active, but not displayed.  This is an known problem with certain nvidia drivers and UEFI, where the driver relies on legacy BIOS functionality which is not present in UEFI.  You can investigate this further through research online and hands-on testing.