This is a disaster and recovery report.
Yesterday I installed BIOS update 6401 for my Asus motherboard from http://www.asus.com/Motherboards/F2A85M_LE/ and as a result, Linux could not boot anymore. It disappeared from the BIOS boot options and was unlisted. This is a phenomenon that is similarly happening to other people as well and is not restricted to my motherboard only. This could not be resolved not even by installing older version of BIOS, reinstalling newer or anything else. The update removed any possibility of running Linux ever again.
A Little History
The conditions under which it is possible to install and use both Windows and Linux are the following. The UEFI version of Windows can use UEFI Secure boot option if it is enabled in BIOS and install to GPT partitioned disk, which is favorable if you use very large disk. The UEFI Secure boot option can be disabled later (Secure boot = Other OS), which is required for booting of Linux that is already installed or will be installed.
UEFI Secure boot functions by using FAT partition mounted at /boot/efi that is shared between operating systems. Any operating system only needs to put its own boot manager file or files in the directory EFI on that partition. BIOS reads this partition and recognizes available boot managers, and thus different operating systems.
Asus is able to boot disk drive correctly only if opensuse manager is the first uefi bootable device on the list in BIOS, windows manager is the second, and everything else comes later. To boot from DVD or CD, the list needs to be rearranged in BIOS temporarily, and later restored to the default order.
You need to restore one critical option after each BIOS update, Secure boot = Other OS in BIOS. However, after update 6041, this does not have any effect.
Restoring the Linux
It is possible to run the OpenSUSE upgrade from the installation DVD, which takes a long time and seems to update large number of files. It would be far more convenient if the upgrade could only update the boot loader - grub2 for EFI systems with default options, in my case, instead of updating many other packages. The contents of /boot/efi are replaced during the upgrade and the OpenSUSE can boot again if you visit the BIOS again and sort the list of UEFI bootable devices.
It is necessary to start the boot loader setup from YaST once again after the reboot so that the grub2 boot loader can recognize Windows, if you have any and add it to the boot menu.
The Rescue CD for OpenSUSE is a waste of time seemingly, because it takes a very long time to load and does not offer explicitly, through a setup or help screen, any options to automatically reinstall the boot loader. Its graphical environment could only load by entering root as a user without any password. Partition manager offers help with mounting partitions and you could try to mount your OpenSUSE root partition from the hard disk on local mnt directory as well as your boot partition (if it exists) on mnt/boot and perform chroot in terminal (assign a root directory to the directory where you mounted your OpenSUSE root partition). Other forum posts suggested this procedure in order to run yast/grub from the hard disk and reinstall grub from hard disk, rather than from CD. This is loosely described in post http://forums.opensuse.org/showthread.php/492039-Repair-Grub2-Efi-Boot-Entry-in-Rescue-Console-form-DVD
However, I did not manage to mount the root directory, because it was encrypted and the partition manager refused to mount it.
Lessons
Companies are capable of downgrading our computers through updates. As a result, they can erase Linux from computers. These situations can be foreseen and documented with honesty and good will on all sides, so that the resolution is automatic. The automatic resolution means that the user feedback has succeed.
