[necovek]

I like to put it on its head: a proper fake for any component should be designed by the authors of the component: they can provide one to the same behaviour relatively cheaply.

With hardware, I try to ask for simulated HW based on the designs, but I usually don't get ever it.

[convolvatron]

If I'm working next to the hardware group, I generally write my own. this allows me to make progress on drivers/firmware before hardware is available. if its an asic we can even spend a little time making it run in the DV environment - they get vectors for free and overall we get more confidence that the firmware/driver is going to work on delivered silicon.

if something doesn't work on actual hardware, now we're in a really good place to have to a conversation. clearly the simulator differs from the actual design, and we can just focus on sussing that out. otherwise the conversation can be alot more difficult and can devolve into 'hardware's broken' vs 'software person doesn't have a clue'.