Too Long; Didn't Read
Firmware is the most powerful software that runs on a platform. It can tear your security concerns apart if configured wrongly, and it can prevent your platform from booting if written faulty. Firmware Development is kind of a monopoly. There are only a hand full of companies who are developing firmware for nearly the complete market of servers and laptops. The majority of the cryptography community relies on open source. Every known and sane cryptographic algorithm or protocol is publicly documented and available. We do not know what is happening on the lowest level of the hardware.