List of public information on Intel x86 microcode and related info
http://www.righto.com/2020/05/extracting-rom-constants-from-8087-math.html
“Extracting ROM constants from the 8087 math coprocessor's die”
Think this site (siliconpr0n.org) might have some images of the bits, but might need a better pass if someone was really serious about it
https://en.wikipedia.org/wiki/Appendix_H
http://computer-programming-forum.com/46-asm/e2e5b0bdcf448270.htm
This was leaked a while back (by accident?) from a research group. Someone also wrote an OpenOCD module to feed instructions in as microcode
Relevant documents?
https://twitter.com/peterbjornx
http://inertiawar.com/microcode/
https://github.com/platomav/MCExtractor
https://github.com/platomav/CPUMicrocodes
IIRC there was also a conference talk I saw
https://github.com/chip-red-pill/glm-ucode
“Five Intel Microcode (uCode) Sequencer's arrays for Atom Goldmont core named according to our guesses”