Ubuntu 14.04 UEFI boot partition and GRUB reinstall problem

[oldfred]

Sorry, Luke M is correct. I reversed the /boot and /efi.
Glad others do check.

If you have the amd64 bit version, then it is the 64 bit version. And will have the capability to boot with UEFI so must have efi files.

[Luke M]

By the way, when you run the ubuntu live CD, the grub-pc package (for BIOS) is installed, not grub-efi-amd64. That's why the grub-install command failed. Try:

sudo apt-get install grub-efi-amd64

[erotavlas]

By the way, when you run the ubuntu live CD, the grub-pc package (for BIOS) is installed, not grub-efi-amd64. That's why the grub-install command failed. Try:

sudo apt-get install grub-efi-amd64

Thank you Luke M, you have stopped my nightmare The right command it is sudo apt-get install grub-efi-amd64

[erotavlas]

This is my final post with a summary of my problem and the corresponding solution in order to avoid to waste your time on resolving it.

The first thing to do is to check if you boot your live Ubuntu system in UEFI mode

[ -d /sys/firmware/efi ] && echo "EFI boot on HDD" || echo "Legacy boot on HDD"

If the answer is "EFI boot on HDD" then you can proceed otherwise you have to modify your boot setting into the BIOS https://help.ubuntu.com/community/UEFI

Then you have to: 1) restore your efi partition and 2) reinstall the GRUB
1) To restore your efi partition
First install efi boot manager

sudo apt-get install efibootmgr

check that your partition is GPT and that you have an efi partition as first partition of your drive https://help.ubuntu.com/community/UEFI

sudo gdisk -l /dev/sda

Then you have to mount your Ubuntu system partition and efi partition. In my case the Ubuntu is located in /dev/sda2

sudo mkdir -p /mnt/system
sudo mount /dev/sda2 /mnt/system

while the efi partition is located in /dev/sda1

sudo mount /dev/sda1 /mnt/system/boot/efi

Finally you have to install one entry into the UEFI BIOS boot list with the following command

efibootmgr -c -d /dev/sda -p 1 -w -L ubuntu

Now you have installed the efi entry for the Ubuntu system.

2) To install the GRUB you have two possibilities. First, for both you have to install this

sudo apt-get install grub-efi-amd64

and now your live Ubuntu is able to install UEFI GRUB.

The first possibility is to manually install the GRUB with these following commands

sudo  grub-install --boot-directory=/mnt/system/boot --bootloader-id=ubuntu  --target=x86_64-efi --efi-directory=/mnt/system/boot/efi --recheck  --debug /dev/sda

and

sudo grub-mkconfig -o /mnt/system/boot/efi/EFI/GRUB/grub.cfg

while the second possibility is a guided procedure using Boot-repair https://help.ubuntu.com/community/Boot-Repair

sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo sh -c "sed -i 's/trusty/saucy/g' /etc/apt/sources.list.d/yannubuntu-boot-repair-trusty.list"
sudo apt-get update
sudo apt-get install -y boot-repair && (boot-repair &)

Now you can launch Boot-Repair and follow the instructions at video. At certain point the Boot-Repair ask to you to launch these commands from terminal

sudo chroot "/mnt/system" dpkg --configure -a
sudo chroot "/mnt/system" apt-get install -fy
sudo chroot "/mnt/system" apt-get install -y --force-yes grub-efi-amd64-signed shim-signed linux-signed-generic

At the end you can boot again your Ubuntu system