I made no claim about what the software needs to run.
A) I read "mockup" as "nonfunctional version." If it works, I would've said something more along the lines of "they hacked up a X-compatible."
B) Saying "hardware X" tells me that it specifically *doesn't* have all the required software to act functionally similar. If it did, you'd just call it "an X."
From Wikipedia:
In manufacturing and design, a mockup, or mock-up, is a scale or full-size model of a design or device, used for teaching, demonstration, design evaluation, promotion, and other purposes. A mockup is a prototype if it provides at least part of the functionality of a system and enables testing of a design.[1] Mock-ups are used by designers mainly to acquire feedback from users.
Note that if it were functional, it would be called a prototype, not a mockup. It sounds like mockups are only really useful for wind tunnel tests, general design feedback, etc.
makes very specific assumptions about the hardware it runs on... so a "hardware mockup" is required
Or, presumably, an emulator.