Bsim/Pcie/ZynqTop.bsv all now define HostType. (when project Top.bsv files need board-specific host signals, they can import this).
create host-specific files for HostType definitions (and define for referencing)
reference HostType definitions in xxxTop.bsv files
change hdmidisplay from using USES_FCLK1 to using IMPORT_HOSTIF
Change examples/echo so that it always takes HostType as parameter