Your component needs to have an SOPC Builder Tcl file created for it, eg. given an Avalon slave peripheral called avs_peripheral.v, you need an associated avs_peripheral_hw.tcl file that describes its interface to SOPC builder. The SOPC Builder Users Guide for Quartus 10.1 (ug_sopc_builder.pdf) describes how to do this.
To get an initial starting point for your _hw.tcl file, you can start SOPC builder, and then select File->New Component, then click on the HDL tab, and point to your avs_peripheral.v file. The component editor will then try to guess what types of signals are on the component, eg. clock, reset, Avalon slave, and conduits (wires that should be exposed at the top of your SOPC builder design). You can then click on the Signals, Interfaces, and HDL parameters tabs and select the appropriate interface for your signals (you'll probably need the users guide open to figure out what to do for each tab).
The guide explains this in more detail, but at least now you know what you are looking for.
Cheers,
Dave
PS. If you look at the zip file I just posted under the thread '
avalon verification; readdatavalid assertion failures' you'll see a fairly complex _hw.tcl example (it extracts SOPC builder GUI parameters and turns them into VHDL generics, and then writes out an instance file). If your component does not use parameters, then its unlikely you'll need to be this complex. However, it may be a useful reference for you.
