Highly recommended read about x86 security: http://blog.invisiblethings.org/papers/2015/x86_harmful.pdf
The author of this paper is also the developer of Qubes OS. They recently added another requirement to laptops who are 'Qubes certified': they must run Coreboot. It's not Libreboot yet, but that is a huge leap forward for x86 security. Hopefully this will trigger vendors to make their hardware Coreboot compatibile. It won't do anything about Intel ME, but it is a step in the right direction.
I ordered a Thinkpad x200 to flash it with Libreboot last week, just to have at least one device without any malware (in RMS sense)
Or Novena? https://www.crowdsupply.com/sutajio-kosagi/novena
Well, let me take a step back and first say that the project is impressive and I really like it.
But the cost is staggering.
"We're in talks with Intel"
"They really want to do this"
"We're going to make a petition to show interest to Intel"
The reality is that even Google with their Chromebooks, despite hiring most of the Coreboot team and shipping volume into the likely millions of units, was unable to persuade Intel. Even for the absolutely tiny set of CPU models they use
It's a bit over-the-top paronoid to expect firmware modifying software in GPU drivers, but I understand their point.
Broadcom publicly released some code, licensed as 3-Clause BSD, to aid the making of an open source GPU driver. The "rpi-open-firmware" effort to replace the VPU firmware blob started in 2016: https://github.com/christinaa/rpi-open-firmware. See more at https://news.ycombinator.com/item?id=11703842
The sad thing is that ME isn't even developed by Intel, but a third party. They sublicense it to Intel. So even if Intel would be willing to distribute the source, they couln't.
TBH, I think there is a lot of focus on this ME technology and I see no reason that at some point someone is going to crack the model or the encryption and reveal exactly what it is doing and how to disable it.