Comment 23 for bug 1668148

On Sun, Jul 08, 2018 at 09:58:23PM -0000, Chris Chambers wrote:
> I have this problem to and my setup is a bit different and i do not see
> a similar setup mentioned here.

> My disc is GPT partitioned, UEFI is disabled and i boot/install in BIOS
> mode but Ubuntu (Lubuntu) is the only OS installed. That is because off
> a BCM4312 wireless chip which i need compile a module for, no binary
> available. Short off getting that compiled driver signed i must disable
> UEFI and use BIOS mode.

> Disc is partitioned; / , swap , /home , no bios-grub or EFI partition.

> Four attempts to install 18.04 all failed. Problem as noted above.
> Installed 16.04 no problem other than install media does boot as UEFI
> and the messages 16.04 installer gives are a bit succinct! but going
> back one stage does fix and install works good.

> During the 18.04 install attempts NO warning messages received.

With Ubuntu 18.04.1 (and effective today with the current bionic daily
images), the expected behavior is:

 - if the install image is booted in UEFI mode, and the target disk does not
   have an EFI System Partition, only the guided installation options which
   create an ESP will be presented.
 - if an ESP is available, both the UEFI and BIOS versions of GRUB will be
   installed to the target disk. If this is done but the system is not
   booted in UEFI mode, the install will not fail due to the inability of
   grub-install to write the boot order to nvram.
 - after reboot, the system should be bootable via either BIOS or UEFI from
   the target disk, as selected by the firmware.

I think this would address your requirements. Do you agree?

Also, please note that compiling kernel modules for hardware drivers does
NOT require you to disable UEFI boot. At most, it requires you to disable
UEFI SecureBoot. If you are using a dkms package for this module (such as
the broadcom-sta-dkms package), the system will guide you through the
process of enrolling a local kernel module signing key into the MOK firmware
database so that you do not have to disable SecureBoot at all.