Rewrite fkms overlay to kms overlay on upgrade of desktop pi image

[Dave Jones]

With the switch to the Wayland desktop in hirsute, the gadget defining the boot partition of the desktop image for the Raspberry Pi was updated to use the KMS overlay ("full" KMS) instead of FKMS ("fake" KMS): https://github.com/snapcore/pi-gadget/commit/5c701c62e9502999a4af3ba0f071bf3b764e1b30

In addition, the camera firmware was disabled with a comment as there may be incompatibilities with it at this time. However, users upgrading from groovy may still have such entries in their boot configuration. We should deal with this by adding an appropriate "quirk" to the release upgrader.

[Dave Jones (waveform)]

Attaching debdiff against current version (21.04.8) which implements this fix. Test package is built in the following PPA:

https://launchpad.net/~waveform/+archive/ubuntu/ubuntu-release-upgrader/+packages

[Brian Murray (brian-murray)]

I think this is going to crash on amd64 (and other architectures) given that the package you are looking for won't be in the cache.

+ if cache['ubuntu-desktop-raspi'].is_installed:
+ self._replace_fkms_overlay()

[Brian Murray (brian-murray)]

I also think changing "distUpgrade" to something slightly more informative, like do-release-upgrade, might help people who run into an error.

[Dave Jones (waveform)]

Ahh, good point -- I had naively assumed it was an arch all package but you're absolutely right it's arm{hf,64} (and besides, it'd be good practice to use a .get there anyway).

On the distUpgrade, should all references be replaced with "do-release-upgrade"? I'm particularly thinking of things like the config.txt backup, currently being named config.txt.distUpgrade (which apes what happens to the apt sources.list). Or should I just be replacing distUpgrade references in the comments?

[Brian Murray (brian-murray)]

Finally, would adding more information to config.txt about why the changes were made help? I'm thinking either link to the bug, to the release notes, or include the code comment in config.txt. That being said I don't know what all is in config.txt so that may not be appropriate.

[Dave Jones (waveform)]

Hmm, config.txt is fairly wide ranging, dealing with things the user generally shouldn't change (which kernel to boot, which initramfs to load) to things they're very likely to change (whether the camera firmware is enabled, overlays to load for things like the fan-shim).

Unfortunately the lines that may need altering may well be spread out across the file so there's not necessarily an ideal location to place a comment but I could certainly adjust things to output such a comment prior to the first line changed and link to this bug.

I'll propose a merge in a bit with the suggestions.

[Launchpad Janitor (janitor)]

This bug was fixed in the package ubuntu-release-upgrader - 1:21.04.9

---------------
ubuntu-release-upgrader (1:21.04.9) hirsute; urgency=medium

  [ Dave Jones ]
  * DistUpgrade/DistUpgradeQuirks.py: Add quirk to rewrite references to fkms
    overlay in Raspberry Pi boot configuration to kms overlay (and disable the
    related camera firmware lines). (LP: #1923673)

  [ Brian Murray ]
  * Run pre-build.sh: updating mirrors, demotions, and translations.

 -- Brian Murray <email address hidden> Thu, 15 Apr 2021 09:29:00 -0700