SOPC Base addresses available in VHDL

Hello

In my system I have a custom avalon master that accesses some of the onchip memory and several FIFOs that are part of my SOPC system. How can I reference the Base Addresses that are defined or assigned in SOPC Builder in VHDL? At the moment I've hardcoded their value but I do not want to have to update these constants everytime I change the SOPC system.

Thanks

jaha