Ubuntu – Force UEFI Installation

bootdual-bootsystem-installationuefiwindows 10

I installed windows 10 on an ssd with a ASRock X99 Extreme4 motherboard.

From windows, I shrank the windows partition to make space to dual boot ubuntu. I used Rufus 2.11 to create a usb with ubuntu 16.04.1.

The BIOS mode is “Legacy” and I’m getting the message about forcing UEFI. I take it that this happens when the usb media has one boot mode that is different from the computer’s BIOS.

I’ve recreating the usb using the three options for the partition scheme options in Rufus but continue to get the same message.

For Secure Boot, I’ve seen this post and get the result that Cmdlet not supported on this platform. That post suggests that

You can install Ubuntu by simply inserting the LiveCD or LiveUSB and doing the installation procedure without any problems.

First, am I correct about the problem and should not force UEFI? If so, how can I make the proper install media?

Best Answer

You first need to figure out whether Windows is booting in BIOS/CSM/legacy mode or in EFI/UEFI mode. See this page of mine for details, but basically, you can check the "BIOS mode" line in System Information; it should read "Legacy" or "UEFI," depending on the boot mode.

With the boot mode known, you need to create a bootable Ubuntu installation USB flash drive that includes the appropriate boot loader. Most (but not all) tools for turning Ubuntu .iso files into bootable USB media can create mediea with either (or both) BIOS-mode and EFI-mode boot loaders. Rufus is one of the more flexible of tools in this respect; it has three options for boot loader and partition table inclusions. See this page of mine for some more comments on this subject.

Note that installing Ubuntu in EFI mode when Windows is in BIOS mode, or vice-versa, is asking for trouble. Such cross-mode installations can work, but they require considerable expertise to set up.

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Ubuntu – This computer currently has no detected operating systems (no UEFI)

Chances are your partition table is damaged, or at least has something quirky about it that the Ubuntu installer doesn't like. The Ubuntu installer relies on libparted, and I wrote a Web page about this problem in parted and related tools here:

http://www.rodsbooks.com/missing-parts/index.html

If I'm right, the easiest way to fix the problem is to run fixparts, which comes with Ubuntu in the gdisk package. It might ask you some questions or simply fix the problem. You may need to type w to save the changes it makes (which it mostly holds in memory until you OK a change).

Note that fixparts can't fix every problem that might cause the symptoms you're seeing. If you're unlucky you'll need to do more extensive repairs. If that's the case, you'll need to post detailed partition information, which you can obtain by typing the following commands:

sudo fdisk -l /dev/sda
sudo gdisk -l /dev/sda

If you've got multiple disks, repeat those commands for all of them.

Ubuntu – Unable to boot newly installed Ubuntu 16.04 using UEFI mode

Finally, I got it to boot in UEFI. The problem is with UEFI firmware which seems buggy. It does require the EFI partition to be the first one in the GPT table. The partition entries in GPT table were unordered. (EFI was the first one on disk, but 4th in the table).

I followed instruction below to fix that:

Boot using Live USB

Backup GPT table

sudo su
swapoff
sfdisk -d /dev/sda > sda.bkp

Modify new table with new order (EFI is the first)

cp sda.bkp sda.new
nano sda.new

sda.new

label: gpt
label-id: 4A4481B5-0322-411E-8D05-552FBE6189AC
device: /dev/sda
unit: sectors
first-lba: 34
last-lba: 976773134

/dev/sda1 : start=        2048, size=      409600, type=C12A7328-F81F-11D2-BA4B-00A0C93EC93B, uuid=BCB6E471-44F7-4C42-81EC-B276F1D6B6E6, name="EFI"
/dev/sda2 : start=     4194304, size=   127924224, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=F1D50A87-ACB2-4868-B1EA-66C3D5223EA4, name="Linux filesystem"
/dev/sda5 : start=   136513536, size=    17825792, type=0657FD6D-A4AB-43C4-84E5-0933C84B4F4F, uuid=515C9B77-B282-4007-8F1A-B0C5D908591E, name="Linux swap"
/dev/sda6 : start=   154339328, size=   715456512, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=AEBBA3F2-F8B6-40C0-ABFE-9F530FC5F641, name="Linux filesystem"
/dev/sda4 : start=   874115072, size=    98463744, type=0FC63DAF-8483-4772-8E79-3D69D8477DE4, uuid=C96E6320-18EA-40B2-BA46-79FC66407917, name="Linux filesystem"

Restore the GPT table
```
sfdisk /dev/sda < sda.new
```

Now, I'm able to boot.

References:

Change the number of the partition from sda1 to sda2
How to renumber GPT partitions on an umounted disk? (simpler but i didn't try it)

Best Answer

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