Ok I got it up and running now and I got the self test to hang obviously since the emulation is not complete but is there an actual problem apart from that?
Selftests does torture the emulation and as it is optional you can just ignore it for now I think as interrupts seems to work just fine from what I can see when the firmware is communicating with the terminal.
Ok, you just need to check how to the IRQ is connected to the 68020 and make sure the driver provides the vector from the DUSCC. It looks like many interrupts can be polled in one go through the 74ALS240 on page 17, question is where the IRQ is routed and if it in fact interrupts the 68020 CPU at all, I may be that it causes a generic interrupt for the 68030 which reads the interrupt source and deals with it, in which case there is no vector from the DUSCC.
It expects some yet unemulated behaviour -- writable RTC registers (Epson 62421 supports this), GPIO pins on the DUSCC (some configuration jumpers are connected there), also expects DP8473 to generate an interrupt after reset via DOR...