> Are you sure that the physical memory is assigned to the same
region. Is
that runtime space pointed by BAR0 or BAR1?
No, it isn’t the same address. That’s why I read the Base Address Register
first. Is there any other way of doing it? I thought that step was
required for PCI devices.
Alternatively, is it also available in I/O space?
Nope.
Another piece of data, though: It turns out that it works fine on the “bad”
motherboard if I ENABLE Plug-and-Play in the BIOS (which we disable by
default). Since the only PNP devices in the system are some “legacy” ISA
devices that have only fixed I/O at location 0x100, I don’t see how that
causes any issue. But that’s clearly the path I have to go down now…