I tried to setup the “EFI System” partition at install time with software RAID1 array. I tried to avoid installing the bootloader to every disk. (I had an RAID1 with spare)
The ubuntu installer allows to set as partition type “EFI System” on the software RAID array. So I thought it would work.
After successful installation the BIOS of the Supermicro mainboard has not found any EFI-Boot partition.
So I destroyed the software RAID of the “EFI System” and installed the bootloader in chroot from a Debian-Live system. I had not to change the partition flag. It was already setup right to “EFI System”
mdadm -S /dev/mdX
mdadm --zero-superblock /dev/sda1
mdadm --zero-superblock /dev/sdb1
mdadm --zero-superblock /dev/sdc1
mount /dev/md[RootFileSystemWithBoot] /mnt
mount --bind /dev /mnt/dev
mount --bind /sys /mnt/sys
mount --bind /proc /mnt/proc
Now we remove the RAID array from config file
Edit your fstab
And last but not least install grub
mount /dev/sda1 /boot/efi
mount /dev/sdb1 /boot/efi
mount /dev/sdc1 /boot/efi
Hint: You have to use a install media or live system which is EFI Boot capable and force BIOS to boot from EFI. (You could use my USB Stick). Otherwise EFI support in Linux is disabled.
I was running Cyanogenmod since I’ve got my m8. Cause of this the firmware never got updated via OTA. When I tried to update my m8 to CM12 custom recovery told me that I’ve got wrong bootloader version to upgrade.
Here is a simple walkthrough to ugprade the firmware without flashing stock firmware and without flashing stock recovery.My device has S-ON and CID is 401.
Now reboot your device to RUU mode and flash firmware via (this may birck your device, be carefully):
fastboot oem rebootRUU
fastboot flash zip 3.28.401.9.zip
At first try (fastboot flash zip 3.28.401.9.zip) did not work out correctly. Try again (don’t reboot) then it should success.
When hopefully everything was correct your device has stock recovery installed and in hboot it shows relocked. You can now unlock your phone normally as you did first time via http://www.htcdev.com/bootloader
After bootloader unlock flash custom recovery and enjoy Android L CM12 on your m8.