I am answering to myself. Both packages shim-signed and grub-efi-amd64-signed were installed and signed with Microsoft UEFI key. ~$ sudo sbverify --cert microsoft-uefica-public.crt /boot/efi/EFI/BOOT/BOOTX64.EFI warning: data remaining[1171248 vs 1334816]: gaps between PE/COFF sections? Signature verification OK ~$ sudo sbverify --cert microsoft-uefica-public.crt /boot/efi/EFI/ubuntu/shimx64.EFI warning: data remaining[1171248 vs 1334816]: gaps between PE/COFF sections? Signature verification OK The problem was coming from Dell BIOS which was not supporting the Secure Boot correctly. I have upgraded BIOS to version 1.9.0 and it works ! I can now boot in Secure Boot mode. Issue fixed in BIOS 1.9.0: Fixed an issue with Secure Boot Option ROM Signature Verification. So XPS 13 9370 users shall upgrade their BIOS in order to have Secure Boot mode functionnal with Dell Ubuntu.
Hi, My third question concerns Secure Boot. I am wondering why the Ubuntu edition laptop is delivered with Secure Boot disabled.Do we agree that Ubuntu 18.04 is compliant with Secure Boot feature ? Thanks. Kind regards, Christophe
XPS 13 9370 Ubuntu Unsecure Boot