Re: 'error: invalid signature' when booting Windows 10

[Pascal Hambourg]

Le 18/12/2018 à 06:20, David Collier a écrit :
> I did this and it booted the main linux installation from the SSD even
> though grub was booted from the USB stick. Is there a way to confirm that
> it booted in EFI mode?

GRUB's environment variables displayed by "set" indicate whether it 
booted in EFI or BIOS mode. In the Linux system, efibootmgr shows the 
EFI boot variables only if booted in EFI mode.

> Also, how exactly do I proceed from here, I re-read this thread but don't
> see what should I do next.

Running grub-install without argument should be enough to install the 
GRUB EFI boot loader, provided that the EFI partition is mounted on 
/boot/efi and grub-efi-amd64-bin is installed. Running update-grub 
should now detect and add Windows to GRUB's menu.

> I ran 'apt-get install grub-efi-amd64', but this did not result in the
> directory /boot/grub/x86_64-efi showing up, it installed a bunch of files
> in /etc/kernel and /usr/share

The package installation should have run grub-install which should have 
populated /boot/grub/x86_64-efi.