Legacy mode issue installing Ubuntu 16.04

[Petter Adsen]

On Fri, 25 Mar 2016 19:59:23 +0100
"Gary J. Kirkpatrick" <garyartista at gmail.com> wrote:

> Thought I'd try Ubuntu 16 alongside my install of 15.10.  When I
> start the install I get the following message:
<snip>
> Since I do want to continue to access 15.10, I want to install in
> legacy mode, which I used to install 15.10 in the first place.  Is
> there some way of overriding the machine's software from within the
> install?    I checked the bios and only Legacy Mode options are
> enabled.

Some machines, and apparently yours, can be set to boot both UEFI and
Legacy systems, and you define in the firmware setup which mode is
tried first. On my system, I can choose between "Legacy only", "UEFI
only", and "Both". I'm guessing your system has a similar setting, and
tries UEFI before it falls back to Legacy mode. Since it is able to
boot the installer in UEFI mode, that is what is started.

Anyway, you will probably need to change something in your firmware
settings, I don't think you can force the installer to install in
Legacy mode on a system that has been booted in UEFI mode.

Of course, you can also convert your Legacy 15.10 install to UEFI by
creating an ESP (EFI System Partition) and installing the
grub-efi-amd64 package (grub-efi-amd64-signed if you use Secure Boot),
and then have both systems in UEFI mode. You need to do this from a
live disc that is booted in UEFI mode and use something like chroot.

Take a look at these if you need a guide:
https://help.ubuntu.com/community/UEFI#Converting_Ubuntu_into_UEFI_or_Legacy_mode
http://askubuntu.com/questions/509423/which-commands-to-convert-a-ubuntu-bios-install-to-efi-uefi-without-boot-repair

Petter

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