Calling exec/AddMemList is the easy way. The harder way would be to have autoconfig for the memory. But since you're in control of the whole HW anyway, why bother...
Autoconfig allows you to call exec/AddMemList from an autoboot "rom" (the rom would be embedded in the fpga image).
All you'd have to do is respond internally to e80000 space until told to shut up, at which point you'd pass on the accesses to the cpu socket.
As you're going to have to have local vs motherboard accesses anyway then it's not going to be much extra logic.
The alternative is a command in s:startup-sequence, but thats boring.
