[geofft]

Sure, but manuals are.

Data has never been copyrightable. Copyright has only ever protected creative expression. Draw your own diagrams and write your own explanations and you're fine. (See iFixit, for instance.)

It's just like how you can't post a copy of The Matrix online but you can definitely write a plot summary without infringing anyone's copyright. Whether it makes sense that manuals (and firmware, for that matter) are considered as worthy of copyright protection as The Matrix is a separate question, but the law sees them the same way.