Looking at how things are routed, I just don't see a way a Nubus card can get any interrupts except its own without the host CPU and and consulting VIA2/RBV. Particularly when the Nubus card is sitting off a Nubus bridge off an 030 PDS. The signals just aren't present.
The Rocket can read VIA2/RBV directly, since it is capable of operating as a Nubus master, but it can't get /SLOTIRQ (or onboard SCSI interrupts, Sound interrupts, Egret-based NMI, etc.) without the host CPU. Once the Rocket has software running on the host CPU, nearly anything is possible, but it still has to work within the constraints of the hardware of the system it is running in while (mostly) preserving software compatibility.
The Rocket does change one thing pretty substantially though: it does complicate any software/ROM-based solutions to this problem since any software would need to be compatible with whatever contortions the Rocket software is doing.
But anyway, that's just my understanding, which is definitely subject to reality checks!
The Rocket can read VIA2/RBV directly, since it is capable of operating as a Nubus master, but it can't get /SLOTIRQ (or onboard SCSI interrupts, Sound interrupts, Egret-based NMI, etc.) without the host CPU. Once the Rocket has software running on the host CPU, nearly anything is possible, but it still has to work within the constraints of the hardware of the system it is running in while (mostly) preserving software compatibility.
The Rocket does change one thing pretty substantially though: it does complicate any software/ROM-based solutions to this problem since any software would need to be compatible with whatever contortions the Rocket software is doing.
But anyway, that's just my understanding, which is definitely subject to reality checks!