HOWTO: Restore GRUB
1) Boot from openSUSE CD into recovery console
2) Type following commands:
grub
find /boot/grub/menu.lst
root (hd0,5)
setup (hd0)
quit
HOWTO: Restore GRUB2
1) Boot from openSUSE DVD
2) Choose Rescue System
3) Log in as root
4) Find out root partition
fdisk -l
5) Mount root partition
mount /dev/sda2 /mnt
6) Mount other devices
mount --bind /dev /mnt/dev
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
7) Change root partition
chroot /mnt OR chroot /mnt /bin/bash
8) Install grub2
grub2-install /dev/sda
9) Exit chroot and reboot
exit; reboot
http://forums.opensuse.org/content/128-re-install-grub2-dvd-rescue.html
HOWTO: Add Windows 8 entry to GRUB2 manually
1) Find out location of Windows 8 boot partition
fdisk -l
2) Find out UUID of Windows 8 boot partition
grub2-probe -t fs_uuid -d /dev/sda3
3) Add following lines to ‘/etc/grub.d/40_custom’
menuentry "Windows 8" {
insmod part_gpt
insmod chain
set root='(hd0,gpt1)'
chainloader /EFI/Microsoft/Boot/bootmgfw.efi
}
OR
menuentry "Windows 8" {
insmod part_gpt
insmod fat
insmod search_fs_uuid
insmod chain
search --fs-uuid --no-floppy --set=root 080F-E6DA
chainloader (${root})/efi/Microsoft/Boot/bootmgfw.efi
}
4) Refresh GRUB2 configuration
grub2-efi-mkconfig -o /boot/grub2-efi/grub.cfg