Restoring Arch bootloader for the future self

  • Grab latest Arch, create a bootable key (do this before you’re doomed)1.

  • Press F2 at boot, change the boot order to start on the key in UEFI mode

  • Boot on Arch, then

# Boot in UEFI mode !!
loadkeys fr
mount /dev/md125p3 /mnt
arch-chroot /mnt /bin/bash
mount /dev/md125p1 /boot/efi/
pacman -S linux
pacman -S grub
grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=grub_uefi --recheck
grub-mkconfig -o /boot/grub/grub.cfg
umount /boot/efi
exit
umount /dev/md125p3
reboot
  • Cross fingers…

In case you need to reinstall all the things2:

sudo pacman -Sy `yaourt -Q | grep -v '^aur'| grep -v '^local' | cut -f2
-d'/' | awk '{ print $1 }'`
  1. Multisystem is pretty handy for this. You can put several OSes on the key, and choose what to boot. http://liveusb.info/dotclear/ 

  2. if you don’t use yaourt, remove the grep part