Have been working on building a multi boot system using EFI. This EFI capable system can not boot Ubuntu or any other installation media using EFI with the only exception being Windows installation media. Most distributions appear to be using grub for their boot manager and boot loader so trying different distributions and tools such as Parted Magic and Boot Repair give same results when trying to boot EFI mode in order for an EFI install to be done.
What happens when trying to boot media EFI mode is if EFI grub manager loads (black screen) and if any choice is selected (Try Ubuntu, Install Ubuntu or Verify) get error can not read disk and the kernel need to be loaded first). There appears to be no explanation online (that I have found so far) that goes anywhere near describing how and why this happens.
The accepted way of installing Ubuntu to an EFI system is apparently switched off EFI and install in legacy mode which involves creating a bios-grub partition before commencing or let boot-repair to do the fix after installing Ubuntu in legacy mode. Boot Repair detects EFI system and creates the bios_grub partition and installs grub-efi.
So after getting Ubuntu and Windows booting using EFI I noticed the grub_bios partition was still in existence so i removed it with gdisk and still have Windows and Ubuntu booting.
Why doesn't boot-repair delete bios_grub partition after installing grub-efi?
14/08/2013 UPDATE: After installing rEFInd boot-repair cd now boots EFI mode.
- Is bios_grub some kind of MBR partition? How does this differ from a protective MBR which is in EFI partition?
Online there is some reference to Secure Boot causing system to throw "you need to load kernel first" error or simply to hang at a black screen. What causes the "you need to load kernel first" error on system that appears to not being using Secure Boot as there is nothing in firmware settings or vendor documentation that mentions this. Windows Upgrade Assistant says this system is not Secure Boot capable.
Are there different versions of Secure Boot?
How to identify if system is Secure Boot capable?
This system uses EFI instead of UEFI. Does this use different Secure Boot?
Why does the UEFI installer not run on this machine?