[Bug 1025555] Re: Ubuntu i386 images are not compatible with 32-bit UEFI computers

[Jonathan]

WARNING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

I have only tested this when booting only ubuntu. Dual-booting has not been tested by this.
If you plan to dual-boot, then USE AT YOUR OWN RISK!!!!!!!!!!!!!!!!

==============================Workaround==============================

Note: Read ALL the instructions before preforming this, up to the set of
==== signs.

First, MAKE A FULL DISK BACKUP!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
Then enable "CSM" (Compatibility Support Module) or Legacy (BIOS) mode. If you do not have this option available, then this workaround will not work :( .
Boot an Ubuntu 12.04 32-bit disk. Use GParted to WIPE EVERYTHING (create a new partition table). This action can NOT be undone. Make a new partition labeled "EFI" (about 200 MB of space, FAT32 format). After the formatting completes, mount it:

sudo mount /dev/sda1 /mnt

Add a folder called "boot". This folder will be empty.
Add a folder called "EFI". Add a sub-folder called "Ubuntu". Leave it empty.
Unmount (the command is called umount, not a spelling error):

sudo umount /dev/sda1

Start the installer. Choose the "Something Else" option. Add a new "swap" partition (make it the size of your memory). Then make a new "ext4" partition with mount-point of "/". Then click the partition labeled "EFI" and select "Change". For the mount point, type in "/boot/efi" (without quotes). Click "Install now"
Ignore warnings about making a BIOS partition, or elimination of files in /etc, /usr, /var... This will not affect the EFI partition. 
Reboot, remove CD/DVD when prompted. Keep legacy mode ON.
Once ubuntu has booted from the HDD (or SSD), install "Synaptic". Then launch synaptic (enter password when prompted). Use it to install "grub-efi-ia32". This will install/uninstall other programs as well. Click apply.
Wait...
Reboot. Turn legacy/CSM to OFF. Problem (should be) solved.
---
If ubuntu doesn't boot, then press a key like F9, F12, ESC, or another key to choose which device to boot. Choose "Boot from EFI file" Select a drive labeled "EFI". Select EFI. Select Ubuntu. Select "grubia32.efi" or "boot.efi". Let ubuntu boot.
---
If you are dropped to an EFI shell, do the same as above, except type "exit" (without quotes) instead of pressing a key.
---
Anything else goes wrong, use your backup to restore to its original state.
======================================================================

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https://bugs.launchpad.net/bugs/1025555

Title:
  Ubuntu i386 images are not compatible with 32-bit UEFI computers

Status in Ubuntu CD image build software:
  Won't Fix
Status in “grub2” package in Ubuntu:
  Invalid
Status in “ubiquity” package in Ubuntu:
  Confirmed

Bug description:
  64bits EFI computer (with GPT disk) with pre-installed 64bits Windows7.
  AND 32bits EFI computer without legacy boot support

  1) Installing Ubuntu 12.04 64bit creates a valid
  /efi/ubuntu/grubx64.efi entry. At reboot, the GRUB menu appears and
  allows to boot Ubuntu.

  2) Installing Ubuntu 12.04 32bits installs grub-pc, which creates no
  EFI entry. Ubuntu can't be booted (except if it is possible to
  deactivate EFI mode).

  3) Installing grub-efi from an already installed Ubuntu32 creates
  /efi/ubuntu/boot.efi , and /efi/ubuntu/grubia32.efi . Both EFI entries
  fail.

  4) Installing grub-efi in an already installed Ubuntu32 in chroot via
  an Ubuntu64 live-CD ( so that grub-efi has access to EFI variables)
  also creates two invalid EFI entries (/efi/ubuntu/boot.efi , and
  /efi/ubuntu/grubia32.efi ).

  CONCLUSION:
  - grub-efi 32bits always creates invalid entries.
  - Installing Ubuntu32 bits on an EFI system should be blocked by Ubiquity (the Ubuntu installer). In this case, Ubiquity should ask the user to install Ubuntu64 instead.
  - the Download page should warn that the 32bits ISO is not compatible with recent (EFI) computers

  === Workarounds ==

  If you have UEFI-only machine, please use amd64 (64-bit) images. That
  image will most likely work for you as your machine is highly likely a
  64-bit one.

  If you truly have 32-bit-only CPU and UEFI-only machines please post
  exact Manufacturer, OEM, make, brand and model number as a comment on
  this bug report.

  Currently known machines that are affected are Intel Atom 32-bit System-on-a-chip based machines, such as phones & tablets as listed on:
  https://en.wikipedia.org/wiki/Atom_(system_on_chip)

  Please note explicit Intel Atom (CPU) architecture has not been
  supported in Ubuntu for a while know. The Atom system-on-chip is a new
  & upcoming type of processors that are not supported by Ubuntu at the
  moment and further work is required to bring up an Ubuntu port to such
  machines. At the moment those machines have limited stock, high
  pricetag and no Ubuntu ports known to be in progress.

  (potential work-around disable secure boot, prepare usb-stick with
  32bit grub-efi image installed, boot of that and perform manual  -
  "debootstrap" based installation: manually partition, manually install
  grub-efi, debootstrap packages, attempt to boot.)

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