Re: x86_64: grub-install for secure boot

[Pascal Hambourg]

On 28/07/2023 at 20:13, Zvi Vered wrote:
> You wrote: "Most likely the system was booted in legacy BIOS mode"

I don't think so. grub-install would have selected the i386-pc target 
instead of x86_64-efi.

> I booted knoppix with: secure boot=disable
> Under this knoppix I ran: grub-install.
>
> Should I boot the PC with secure boot=enable and then run grub-install ?

I do not think it would change anything. As I suggested previously, 
you'd rather check efivarfs first. If it cannot be mounted, run 
grub-install with option --force-extra-removable and select to boot from 
the drive removable media path (not the "debian" boot entry).