[Bug 1015211] Re: Ubiquity installed grub-efi when it should have installed grub-pc

[Steve Langasek]

> - the disk is Ms-Dos (not GPT)

This is not relevant.  UEFI does not require a GPT to boot; there is a
specification for a declaration of EFI System Partitions on an MBR-only
disk.

> - and Windows was installed in Legacy mode ( there is no EFI
partition)

Also not relevant.  To grub-installer, this just looks like a system
that has an unbootable copy of Windows sitting on the disk.

Fundamentally, the problem here seems to be that the CD *is* booted in
UEFI mode, but the firmware won't use UEFI when booting the OS from
disk.  That sounds like a firmware bug, and one I have no idea how to
work around.  It should be obvious that if the firmware booted the CD
under UEFI, the firmware is UEFI and we should install grub-efi to the
install disk too.

It would be absolutely incorrect to blindly install grub-pc on systems
that have clearly booted using EFI.  Likewise, installing grub-pc
instead of grub-efi based on the detection of non-EFI OS installs would
trade one set of bugs for another.  The only reliable fix here would be
to know that this buggy firmware is in such an EFI-only-on-CD mode and
install grub-pc in that case.

(Alternatively, we could rearchitect the grub packages so that we are
always installing both grub-efi and grub-pc on all installs, something
that I increasingly believe we need to be doing in order to support
users across the BIOS->EFI threshold.  But eventually we would want to
drop grub-pc from EFI systems anyway, so this bug could still be a
problem.)

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https://bugs.launchpad.net/bugs/1015211

Title:
  Ubiquity installed grub-efi when it should have installed grub-pc

Status in “ubiquity” package in Ubuntu:
  Incomplete

Bug description:
  Goal:
  Create a dual boot system with a pre installed Win7x64 and Ubuntu Desktop 12.04 LTS amd64 with Grub installed as the boot-loader in the MBR of sda.

  Problem symptoms:
  After Ubuntu installation from the Live CD along side Win7x64, Grub wont start at boot-up of the system. It boots straight into Win7.

  Hypothesis:
  The Ubuntu Desktop 12.04 amd64 Live CD, was booted with an UEFI boot sequence although the hard disk structure is MSDOS with MBR. This fools ubuquity into installing Grub in EFI mode and does not install grub-pc into the MBR.

  For full information please view:
  http://ubuntuforums.org/showthread.php?p=12030957#post12030957

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