UC20 on RPi3B fails to boot


I’m trying to boot latest UC20 image on my RPi3B:

Here is the serial output I see:

Seems like the boot relies on a TPM being present which isn’t the case. Any ideas?


Your error is not about the TPM being absent, this is the error:

[   49.768448] the-tool[[209]: FAILEDerror: cannot load metadata and verify essential bootstrap snaps [base kernel snapd gadget]: cannot validate "/run/mnt/ubuntu-seed/snaps/pi-kernel_232.snap" for snap "pi-kernel" (snap-id "jeIuP6tfFrvAdic8DMWqHmoaoukAPNbJ"), hash mismatch with snap-revision] 
Failed to start the-tool.service.

Are you sure you booted the image exactly as it is in provided on cdimage and didn’t modify it? It seems that the image was tampered with or maybe got corrupted during download.

Correct, I re-downloaded / re-flashed and it worked. Sorry for the noise.

Do you happen to know where the pi-kernel snapcraft.yaml is?

Anyway I’ll close this thread, thanks!

Yes, the pi-kernel snapcraft.yaml is here: https://git.launchpad.net/~canonical-kernel-snaps/+git/kernel-snaps-uc20/tree/snapcraft.yaml?h=pi which has the source line which you can use to find the actual kernel source.

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