AVM Fritz!Box 5590

So it looks like (general) the Falcon CPU stuff is working. This device seems to run kernel 4.9 - which is what the WAV300 devices that got a source release use.

Evidently it's still attractive price-wise to buy a stack of these older chips and release a working product.

True. I keep fancying having a go at the DECT stuff - but that does not look hopeful regarding the older sources that are available.

The modem isn't really a modem. It's a PON. It's not simply an SFP, since a PON has to handle the ATM layer also. SFP would have been great (and easy). But with a 2.5G PHY, one could get by. It's definitely a new logic block which I don't think openwrt deals with today.