Ubuntu • Re: Ubuntu 24-04 desktop64 installation fails

Time to follow up on this now I've got some more concrete information. First off: I replicated this over the weekend with a Pi 4 and a Pi 5, and it seems quite reliable to reproduce. I've opened an issue against ubiquity (the old installer we're still using on the Pi images) on Launchpad to track further updates, but I figured I'd post an update here too so people don't have to go clicking around.

Workarounds

I found a few workarounds at the weekend, but they were all pretty horrid, quite random, or unreliable (and therefore not useful). However, this morning I've found a rather simpler workaround which I think may be viable. It appears reliable on the Pi 4 across a couple of drives, and I'd be grateful for further testing on a wider variety of hardware. Specifically:

• After writing the image to the drive, but before booting it, find "config.txt" on the boot partition and open it in a text editor
• Find the "dtoverlay=vc4-kms-v3d" line under the "[all]" section
• Append ",cma-128" to it and save the file
• Unmount the drive cleanly
• Boot the drive on your Pi 4 or 5

In other words, the following lines should from:
To:
There is another vc4 line a bit further down that already has the suffix; you can ignore that one (it's working around another issue on the server images, though I'm now wondering if that's related). This change can be reverted (if necessary) after initial setup has completed.

Root Cause and Fixes

Given that:

• The crash happens immediately upon display of the slides in the installer, which uses webkit
• The slide corruption is a known issue of webkit under Xorg
• That known issue is now associated with a crashing issue
• The crash is potentially worked around by messing with the size of the CMA (contiguous memory area) used by KMS

My current thinking is this is all related, and that fixing up mesa and/or webkit will likely resolve things. I'll build some custom images once fixes for those appear in the archive and re-test.

Statistics: Posted by waveform80 — Tue Apr 30, 2024 9:37 am

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