I found a technology whitepaper from Curtiss Wright (Is Arm the Future for Airborne Platforms in Military and Aerospace?) that makes the following statement in relation to a DO-254 certified project done with the NXP LS1043A:
"NXP provides documentation from the processor’s design, development and manufacturing stages that allows board manufacturers to demonstrate adherence to DO-254 requirements without the complex and time-consuming undertaking of conducting these internal tests themselves."
I previously found EUF-SNT-T1469, that provides a high-level overview of NXP's process in Avionics/Defense applications, but not nearly enough details to build a certification case. I'm interested to get more information about the level of documentation and support NXP is willing to provide from the design, development and manufacturing stages that would allow board manufacturers to demonstrate adherence without having to conduct some internal tests.
I would also be interested in Certification precedence for these cores