Today, I brought my system down to change a plug on the onboard sound card. When I tried to bring it up, I got the "No operating system found" message. I'm single booting openSUSE 12.3 with the UEFI FAT32 partition and the root partition on a SSD. The tmp and home partitions are on a 1T mechanical drive. This system had not been down for quite some time, so there were several YOU updates done, and I did update evolution from build.opensuse.org/GNOME.
The machine was OK, I could boot a KDE Live CD copy, but the SSD drive was not showing up as bootable in the BIOS screen. First move, update the BIOS on my system board. Didn't help. I was concerned that the SSD drive was going bad. After starting with the Live CD, I poked around for a while and could read and write to the FAT partition of the SSD. I started the machine with a copy of Super Grub2, it found the grubx64.efi file on the SSD and the computer came up like it should. Proved the SSD was still working. I ran grub2-mkconfig without success. I'll spare you the long list of stuff I tried but found that, in order to accept a device as bootable, there had to be a FAT partition, with a folder named EFI, containing a folder containing a valid .efi file.
The default file structure on the UEFI FAT partition is /EFI/opensuse/grubx64.efi. With that structure, my computer will not boot. I had to change the name of both the opensuse folder and the grubx64.efi file. If I change the folder named opensuse to anything else, the machine will start to come up, but will not finish. When I change the name of grubx64.efi to anything else, the machine will boot properly as long as the opensuse folder has been renamed.
Obviously, the problem is not in openSUSE, but in grub2. On 16 August, there was an update to grub. Grub2, grub2-efi, grub2-x86_64.efi and so on were contained in the YOU update I did. I find it hard to believe though, that I'm the only one who had a problem. Although my system is operating now, I'm concerned that, in the future, something will require an update to something in grub that will break it again.
I'm hoping that if someone does have a problem, this message will help. But, I'm hoping even more that someone will say "Oh, you didn't need to do all that, dummy, here's how to fix it!"
Bart
The machine was OK, I could boot a KDE Live CD copy, but the SSD drive was not showing up as bootable in the BIOS screen. First move, update the BIOS on my system board. Didn't help. I was concerned that the SSD drive was going bad. After starting with the Live CD, I poked around for a while and could read and write to the FAT partition of the SSD. I started the machine with a copy of Super Grub2, it found the grubx64.efi file on the SSD and the computer came up like it should. Proved the SSD was still working. I ran grub2-mkconfig without success. I'll spare you the long list of stuff I tried but found that, in order to accept a device as bootable, there had to be a FAT partition, with a folder named EFI, containing a folder containing a valid .efi file.
The default file structure on the UEFI FAT partition is /EFI/opensuse/grubx64.efi. With that structure, my computer will not boot. I had to change the name of both the opensuse folder and the grubx64.efi file. If I change the folder named opensuse to anything else, the machine will start to come up, but will not finish. When I change the name of grubx64.efi to anything else, the machine will boot properly as long as the opensuse folder has been renamed.
Obviously, the problem is not in openSUSE, but in grub2. On 16 August, there was an update to grub. Grub2, grub2-efi, grub2-x86_64.efi and so on were contained in the YOU update I did. I find it hard to believe though, that I'm the only one who had a problem. Although my system is operating now, I'm concerned that, in the future, something will require an update to something in grub that will break it again.
I'm hoping that if someone does have a problem, this message will help. But, I'm hoping even more that someone will say "Oh, you didn't need to do all that, dummy, here's how to fix it!"
Bart