Another minor victory in my quest to get more familiar with OpenSolaris. I’ve upgraded to Nexenta unstable, and I noticed a package called sunwaudiohd being installed. That looked like a promising solution to the lack of audio on my OpenSolaris machine - the Intel HDA soundcard has never worked under any version I’ve used.
Sadly, the mere presence of this driver didn’t seem to fix things (it’s never that simple). A little research confirmed that it was the right driver, but that this bug had been discovered. The workaround noted:
update_drv -a -i '"pci8086,27d8"' audiohd
…seemed to do the trick and now I have excellent sound coming from my machine again.