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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?

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1 Answer 1

Boot-Repair does not create nor delete partitions.

During a BIOS install on gpt partitioned drive, Ubuntu will create a bios_grub partition. It did not used to as when I installed with 10.10, I had to manually create the bios_grub.

It is only 1MB, so it is not taking up any room on most new systems. That much space is lost in the new rounding for compatibility with SSDs & 4K drives.

But once you are booting with UEFI then you can delete the bios_grub partition as you need either the efi partition for UEFI boot or the bios_grub partition for BIOS boot. I typically suggest for new drives to have both partitions at the start of a gpt drive and then you can install either way or easily change later. Often difficult to add an efi partition near start of a drive that is already full of data. So then converting to UEFI is difficult.

Updates. If starting with a blank drive and wanting secure boot, this series of videos may help. You have to install keys to make it work with secure boot.

Intel - Install Ubuntu 12.10 part 3 of series for new system w/secure boot, part one install keys, part 2 install Windows 8 YOu may want all three parts.

https://www.youtube.com/watch?v=_cEwj8bBBC4

Are you using 12.04.2? It may be this naming issue?

https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1172065

share|improve this answer
    
There is much 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 sytem 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? –  user420420 Aug 14 '13 at 20:37
    
Is bios_grub some kind of MBR partition? How does this differ from a protective MBR which is in EFI partition? –  user420420 Aug 14 '13 at 20:37
    
Why does the UEFI installer not run on this machine? –  user420420 Aug 14 '13 at 20:43
1  
in the GPT setup, there is no space following the 512-byte MBR for embedding the "second stage" core.img. So part of grub is in protective MBR and some is in the bios_grub partition when using BIOS to boot with gpt partitioning. UEFI uses an efi partition to boot, not the protective MBR and bios_grub partition. –  oldfred Aug 15 '13 at 0:44

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