Comment # 20 on bug 955493 from boo35 boo35

> Please run update-bootloader --reinit;


efibootmgr -v
    (empty)

ls -alR /boot/grub2/grub.cfg
    -rw------- 1 root root 8.5K Nov 19 09:50 /boot/grub2/grub.cfg

update-bootloader --reinit

> it should reinstall GRUB/shim
> (whatever is set in configuration) and recreate grub.cfg. 

ls -alR /boot/grub2/grub.cfg
    -rw------- 1 root root 8.5K Nov 19 09:54 /boot/grub2/grub.cfg
ls -l /boot/efi /boot/efi/EFI/opensuse
    /boot/efi:
    total 8.0K
    drwxrwxr-x 4 root root 4.0K Mar 28  2015 EFI/
    -rwxrwxr-x 1 root root   42 Nov 18 13:58 startup.nsh*

    /boot/efi/EFI/opensuse:
    total 23M
    -rwxrwxr-x 1 root root  297 Nov 19 09:54 grub.xen-files*
    -rwxrwxr-x 1 root root 133K Nov 19 09:53 grubx64.efi*
    -rwxrwxr-x 1 root root  16M Nov 19 09:49 initrd-4.3.0-4.g734b32c-xen*
    -rwxrwxr-x 1 root root 5.1M Nov 15 03:48 vmlinuz-4.3.0-4.g734b32c-xen*
    -rwxrwxr-x 1 root root 3.2K Nov 19 09:54 xen-4.6.0_02-397.cfg*
    -rwxrwxr-x 1 root root 2.1M Nov 11 13:18 xen-4.6.0_02-397.efi*

> Show efibootmgr -v immediately before reboot.

efibootmgr -v
    BootOrder: 0000
    Boot0000* opensuse     
HD(2,1000,96000,6196ccc5-1e27-48e6-8372-2e64118e5d03)File(\EFI\opens)

> What happens after reboot then?
shutdown -r now
    ...

The system drops to the EFI Shell, waits a few seconds then autoproceeds

    ...
      blk1D :BlockDevice - Alias (null)
             PciRoot(0x0)/Pci(0x1f,0x2)/Sata(0x5,0x0)

    Press ESC in 1 seconds to skip startup.nsh, any other key to continue. 
    startup.nsh> fs0:\EFI\XEN\xen.efi 
    Xen 4.6.0_02-397 (c/s ) EFI loader
    Using configuration file 'xen.cfg'
    vmlinuz-xen: 0x000000002beee000-0x000000002c3efac0
    initrd-xen: 0x000000002af8e000-0x000000002beed74c
    0x0000:0x00:0x19.0x0: ROM: 0x10000 bytes at 0x329c6018
    0x0000:0x04:0x00.0x0: ROM: 0x8000 bytes at 0x329b6018
    0x0000:0x10:0x00.0x0: ROM: 0x10800 bytes at 0x3299e018
     __  __            _  _    __    ___     ___ ____    _____ ___ _____ 
     \ \/ /___ _ __   | || |  / /_  / _ \   / _ \___ \  |___ // _ \___  |
      \  // _ \ '_ \  | || |_| '_ \| | | | | | | |__) |__ |_ \ (_) | / / 
      /  \  __/ | | | |__   _| (_) | |_| | | |_| / __/|__|__) \__, |/ /  
     /_/\_\___|_| |_|    |_|(_)___(_)___/___\___/_____| |____/  /_//_/   
                                       |_____|                           
    (XEN) Xen version 4.6.0_02-397 (abuild@suse.de) (gcc (SUSE Linux) 4.8.5)
debug=n Tue Nov 10 5
    ...

to a system login

    Welcome to openSUSE Leap 42.1 - Kernel 4.3.0-4.g734b32c-xen (xvc0).

    xensvr login: 

I never see a GRUB menu.