Grub efi does not execute /efi/boot/grub.cfg and goes in shell mode

[Nicolas Gama]

After installing Ubuntu 15.04 in efi mode, grub efi amd64 does not boot properly:
when the computer boots, it goes directly into grub shell mode,
it does not execute the grub.cfg configuration file in the efi partition (either /efi/boot/grub.cfg or /efi/ubuntu/grub.cfg, depending on whereas the --removable option was provided or not).

from the grub shell, executing the following command resumes normal boot operations.
configfile /efi/boot/grub.cfg
or
configfile /efi/ubuntu/grub.cfg

Reproduce this bug:

install grub with:
the alternate cd (regular ubuntu installation)
or
grub-install --target x86_64-efi --efi-directory ... --root-directory ...
or
grub-install --target x86_64-efi --efi-directory ... --root-directory ... --removable

and try to reboot.

ProblemType: Bug
DistroRelease: Ubuntu 15.04
Package: grub-efi-amd64 2.02~beta2-22ubuntu1.1
ProcVersionSignature: Ubuntu 3.19.0-18.18-generic 3.19.6
Uname: Linux 3.19.0-18-generic x86_64
ApportVersion: 2.17.2-0ubuntu1.1
Architecture: amd64
CurrentDesktop: LXDE
Date: Tue Jul 28 10:51:54 2015
SourcePackage: grub2
UpgradeStatus: No upgrade log present (probably fresh install)

[Nicolas Gama (gama-nicolas)]

More information:
it seems that the prefix is wrongly set when normal.mod is loaded:

echo $root shows (hd0,gpt1)
echo $prefix shows (hd0,gpt1)/boot/grub

On my system, (hd0,gpt1) is the EFI System partition and the linux root is (hd0,gpt3)

This means that normal.mod is looking for (hd0,gpt1)/boot/grub/grub.cfg instead of (hd0,gpt1)/efi/boot/grub.cfg

I guess that the right prefix should be (hd0,gpt1)/efi/boot ?
Is it grub-mkimage or grub-install who does this mistake?

In any cases, copying /efi/boot/grub.cfg to /boot/grub/grub.cfg inside the EFI partition is a dirty workaround, but it will works until a fix is committed.

[Phillip Susi (psusi)]

What argument did you give to --root-directory? You shouldn't need the argument unless you are booted from a livecd and aren't chrooted into your installed system. If you specified /boot/efi, then that would be the problem: it should be your root directory.

[Nicolas Gama (gama-nicolas)]

I tried first without --root-directory, then with
--root-directory /
from the system itself.

Then, from a live USB, I tried using --root-directory /mnt/bla (where /mnt/bla was the mount point)

They all give the same result: the system doesnt boot, we are left with the grub shell where root and prefix point inside the EFI system partition.

[Launchpad Janitor (janitor)]

[Expired for grub2 (Ubuntu) because there has been no activity for 60 days.]