How do you configure the pcie root port on the Stratix 10 to allow the HPS to map an I/O BAR?

I'm not really sure how to proceed, as I don't think we're going to come to a conclusion here. I have been working from the rocketboards PCI link from day 1, which doesn't use an I/O bar, and I have also read the knowledge base article you linked on several occasions while googling. The problem with what the knowledge base solution (using the CRA port), is that it nowhere does it tell you where it is legal to map to in that region. The CRA port is used by the bridge driver and has custom translations for driver-ish configuration stuff. But its external interface is not defined. Only its base address. You can't just map to a random part of it or everything breaks. I've actually tried it.

So, if you don't have any further suggestions, then go ahead and close this and I'll explore other options.