[There was a time when I had bandwidth to read all new IETF RFCs and I-Ds that came out each day. Sigh…]
There is a new IETF Internet Draft from the “anima Working Group” about storing private keys in embedded devices. Sandelman Software Works and Huawei Technologies are authors. There are other documents from this working group as well.
This document provides a nomenclature to describe ways in which manufacturers secure private keys and public trust anchors in devices.
https://datatracker.ietf.org/doc/draft-richardson-secdispatch-idevid-considerations/
https://datatracker.ietf.org/wg/anima/about/
https://datatracker.ietf.org/wg/anima/documents/
https://tools.ietf.org/wg/anima/
Firmware Security 