How to Install to boot both UEFI & BIOS?

[stephane]

have you check this ?

Grub rescue: unknown filesystem

see this topic if you need to chroot for grub restore sudo su cryptsetup luksOpen /dev/sdaX crypto ( here volume mapper encrypted ) cryptsetup luksOpen /dev/sdaY swap ( case out encrypted ) mount /dev/mapper/crypto /mnt mount /dev/sda1 /mnt/boot/efi ( if you need Efi ) mount -t proc proc /mnt/proc mount -t sysfs sys /mnt/sys mount -o bind /dev /mnt/dev mount -t devpts pts /mnt/dev/pts/ chroot /mnt grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=manjaro --rech…