Build focal pi images using the classic branch (aka to enable the pi zero 2 support)

[Łukasz Zemczak]

[Impact]

Right now focal pi images build using the 18 branch - the one we use for UC18. This made sense at the time, as we wanted to keep using one common branch for all use-cases as long as possible. Sadly, with time, classic needs diverged from what we used for core. Also, the current state anyway makes no sense as we build focal images with 18 (where UC18 was bionic based?!) branch code - confusing!

Recently we needed to do changes to the pi-gadget tree to enable support for a new Pi device, and doing it via the 18 branch would be risky - since we'd also have to then add those changes to the UC18 code-base. Using the 20 branch is unwise as UC20 has a different model than classic (due to all the UC20 constrains). So it was decided that we'll simply switch to using the classic branch as we do for all groovy+ images. Dave prepared all the changes to make sure the classic branch conditionally generates images per focal existing standards.

[Test Case]

* With the -proposed livecd-rootfs, build classic raspi arm64 and armhf images
* Boot them on a few Raspberry Pi images, making sure that they still build and work correctly
* Boot the same image on a Pi Zero 2, making sure it boots correctly
* Check with certification that the daily proposed images work correctly on all the tested Pi's

[Regression Potential]

As we're basically switching branches to a completely new series-dependent codebase using a lot of conditionals, there is a high risk of regressing. The newly created images should be thoroughly tested manually and by the certification team on all Pi images, making sure no boot issues have been introduced.
It's risky, but sadly we have no other choice if we want to sanely support the new device.

[Brian Murray (brian-murray)]

Hello Łukasz, or anyone else affected,

Accepted livecd-rootfs into focal-proposed. The package will build now and be available at https://launchpad.net/ubuntu/+source/livecd-rootfs/2.664.39 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 on 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, what testing has been performed on the package and change the tag from verification-needed-focal to verification-done-focal. If it does not fix the bug for you, please add a comment stating that, and change the tag to verification-failed-focal. In either case, without details of your testing we will not be able to proceed.

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

N.B. The updated package will be released to -updates after the bug(s) fixed by this package have been verified and the package has been in -proposed for a minimum of 7 days.

[Ubuntu SRU Bot (ubuntu-sru-bot)]

All autopkgtests for the newly accepted livecd-rootfs (2.664.39) for focal have finished running.
The following regressions have been reported in tests triggered by the package:

livecd-rootfs/2.664.39 (amd64)

Please visit the excuses page listed below and investigate the failures, proceeding afterwards as per the StableReleaseUpdates policy regarding autopkgtest regressions [1].

https://people.canonical.com/~ubuntu-archive/proposed-migration/focal/update_excuses.html#livecd-rootfs

[1] https://wiki.ubuntu.com/StableReleaseUpdates#Autopkgtest_Regressions

Thank you!

[Łukasz Zemczak (sil2100)]

Per Dave's comments:

13:51 < waveform> sil2100, .4 images looking good -- armhf and arm64 booted out of the box on 3B, 4B, and Pi Zero 2, wifi working, bluetooth working. I'll start filling in the focal daily iso tracker in a bit

Certification will test it more during our usual daily image testing. So I consider this good to go.

[Launchpad Janitor (janitor)]

This bug was fixed in the package livecd-rootfs - 2.664.39

---------------
livecd-rootfs (2.664.39) focal; urgency=medium

  * Switch to building raspi classic images using the 'classic' branch instead
    of '18'. This is needed for proper Pi Zero 2 support (LP: #1960950).

 -- Łukasz 'sil2100' Zemczak <email address hidden> Tue, 15 Feb 2022 18:59:05 +0100

[Brian Murray (brian-murray)]

The verification of the Stable Release Update for livecd-rootfs has completed successfully and the package is now being 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.