Add support for running a 64-bit Linux kernel on a 32-bit EFI.

[Shih-Yuan Lee]

[Impact]

* Some platforms only have 32-bit EFI BIOS. When executing `grub-install` on them, it will make the system can not boot up again because of the wrong GRUB EFI payload and UEFI boot entry.

[Test Case]

* Executing `grub-install` on a 32-bit EFI platform should appear the following results.

$ sudo grub-install
Installing for i386-efi platform.
Installation finished. No error reported.

$ sudo efibootmgr -v
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000
Boot0000* ubuntu HD(1,GPT,b8d7d8e9-4ac4-46cc-8bd0-8d90d6df1df4,0x800,0x100000)/File(\EFI\ubuntu\grubia32.efi)

* Executing `grub-install` on a 64-bit EFI platform should appear the following results.

$ sudo grub-install
Installing for x86_64-efi platform.
Installation finished. No error reported.

$ sudo efibootmgr -v
BootCurrent: 0000
Timeout: 0 seconds
BootOrder: 0000
Boot0000* ubuntu HD(1,GPT,b8d7d8e9-4ac4-46cc-8bd0-8d90d6df1df4,0x800,0x100000)/File(\EFI\ubuntu\shimx64.efi) or \EFI\ubuntu\grubx64.efi if there is no grub-efi-amd64-signed installed.

[Regression Potential]

* This patch is directly backported from Ubuntu 16.04 so it should be OK without any regression.

[Other Info]

1) The release of Ubuntu you are using, via 'lsb_release -rd' or System -> About Ubuntu
Ubuntu 14.04

2) The version of the package you are using, via 'apt-cache policy pkgname' or by checking in Software Center
grub2 2.02~beta2-9ubuntu1.8

3) What you expected to happen
Executing `grub-install` will install platform files by i386-efi on 32-bit UEFI BIOS.

4) What happened instead
It installed platform files by x86_64-efi instead.

P.S. Ubuntu 16.04 doesn't have this issue.

[Shih-Yuan Lee (fourdollars)]

This patch is backported from Ubuntu 16.04.

[Martin Pitt (pitti)]

Please add a test case so that this can be verified. Particulary, please add some analysis about regression potential, as boot loader induced changes are highly sensitive to causing fatal regressions.

[Martin Pitt (pitti)]

Hello Shih-Yuan, or anyone else affected,

Accepted grub2 into xenial-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/grub2/2.02~beta2-9ubuntu1.11 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Martin Pitt (pitti)]

Sorry, the previous comment was meant to say "trusty", not "xenial".

[Adam Conrad (adconrad)]

Hello Shih-Yuan, or anyone else affected,

Accepted grub2-signed into trusty-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/grub2-signed/1.34.13 in a few hours, and then in the -proposed repository.

Please help us by testing this new package. See https://wiki.ubuntu.com/Testing/EnableProposed for documentation how to enable and use -proposed. Your feedback will aid us getting this update out to other Ubuntu users.

If this package fixes the bug for you, please add a comment to this bug, mentioning the version of the package you tested, and change the tag from verification-needed to verification-done. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed. In either case, details of your testing will help us make a better decision.

Further information regarding the verification process can be found at https://wiki.ubuntu.com/QATeam/PerformingSRUVerification . Thank you in advance!

[Launchpad Janitor (janitor)]

This bug was fixed in the package grub2 - 2.02~beta2-9ubuntu1.11

---------------
grub2 (2.02~beta2-9ubuntu1.11) trusty-proposed; urgency=medium

  * Add support for running a 64-bit Linux kernel on a 32-bit EFI.
    (LP: #1591818)

 -- Shih-Yuan Lee (FourDollars) <email address hidden> Wed, 08 Jun 2016 13:53:40 +0800

[Martin Pitt (pitti)]

The verification of the Stable Release Update for grub2 has completed successfully and the package has now been released to -updates. Subsequently, the Ubuntu Stable Release Updates Team is being unsubscribed and will not receive messages about this bug report. In the event that you encounter a regression using the package from -updates please report a new bug using ubuntu-bug and tag the bug report regression-update so we can easily find any regressions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package grub2-signed - 1.34.13

---------------
grub2-signed (1.34.13) trusty; urgency=medium

  * Rebuild against grub-efi-amd64 2.02~beta2-9ubuntu1.11 (LP: #1591818)

 -- Martin Pitt <email address hidden> Mon, 04 Jul 2016 13:15:40 +0200

[Phillip Susi (psusi)]

This was not fixed in grub2-signed: it still does not produce a 32 bit signed package, only the amd64 one. This prevents the signed stub from being installed on a 32 bit EFI system, as in bug #1644915.

[Ubuntu Foundations Team Bug Bot (crichton)]

The attachment "grub2_2.02~beta2-9ubuntu1.9.debdiff" seems to be a debdiff. The ubuntu-sponsors team has been subscribed to the bug report so that they can review and hopefully sponsor the debdiff. If the attachment isn't a patch, please remove the "patch" flag from the attachment, remove the "patch" tag, and if you are member of the ~ubuntu-sponsors, unsubscribe the team.

[This is an automated message performed by a Launchpad user owned by ~brian-murray, for any issue please contact him.]

[Phillip Susi (psusi)]

A year and a half later and still there is no 32 bit signed grub.