The creator of systemd (Lennart Poettering) has recently created a new company dedicated to bringing hardware attestation to open source software.
What might this entail? A previous blog post could provide some clues:
So, let’s see how I would build a desktop OS. The trust chain matters, from the boot loader all the way to the apps. This means all code that is run must be cryptographically validated before it is run. This is in fact where big distributions currently fail pretty badly. This is a fault of current Linux distributions though, not of SecureBoot in general.
If this technology is successful, the end result could be that we would see our Linux laptops one day being as locked down as an Iphone or Android device.
There are lots of others who are equally concerned about this possibility: https://news.ycombinator.com/item?id=46784572


Secureboot is worthless if the Microsoft keys are still enabled. It should only allow code that you sign yourself to boot.
If the end user can arbitrarily sign code themselves that is bootable then it kind of defeats the purpose of secure boot.
The whole idea is that it makes it impossible to start if the chain of trust is broken.
It keeps someone from booting code that hasn’t been signed with my key. That’s the whole point of secure boot. If someone else has the key, then it’s not secure anymore.