Huh, so that's why the iPhone 6s's SecureROM memory regions weren't MMU-locked... IOMMU doesn't come in ARM by default! So you have to wire it up yourself (in your own IP blocks), and then hook it up in software everywhere you want it to work.

And all that costs extra developer time -and money.

Heh.

http://ramtin-amin.fr/#nvmedma