>
> If I choose to install plan9, I get a result shown in the attached
> a.png (and it does not proceed any further).
>
> If I choose to just boot (not install), it gets stuck after
> init: starting /bin/rc
> and shows the same 'spurious interrupt 39'.
>

Try to play with AHCI settings in BIOS.
IIRC I had similar problems with my IntelAtom based M/B.

Pavel