I'm looking for an alternative to Chrome OS (yes I know it's linux)

I was using Chrome OS on a netbook and am now trying to find a distro that will boot directly to Firefox with nothing else in the way.

Minimalist is the way to go here since the netbook only has a single core CPU and 2 GB of ram.

I've tried several flavors of puppy linux with no luck.
Tried Browser Linux but it doesn't seem to be getting updates anymore.

Had general success with Porteus (kiosk) with speed and minimalism (I actually like it), but trying to configure it and install add ons to the browser (like adblock+) required me to jump through more hoops than a circus poodle.

So what options am I missing? Anything obvious?

Even looked at GalliumOS but that's geared toward Chromebooks and Chromeboxes and will likely not work with my old netbook hardware.