Oh, ok, I think I see the confusion. /proc/device-tree is just a plain text representation of the device tree. It's to let developers work out whether the firmware's giving them something broken. Userspace should never need to use it, and that's why Kay's objecting to an attempt to make userspace use it. The reason it's an issue in this case is that there's no generic kernel interface to say "This machine is a model X made by manufacturer Y" - we'd use the DMI interface on x86, but DMI is a spec that doesn't exist on ARM.