"...tools like SerialICE which runs the firmware in QEMU and forwards IO and MMIO to the actual hardware..."

I never knew about SerialICE prior to reading this article, or that it could forward IO/MMIO to actual hardware (i.e., act as a proxy)... In the past I was curious if a debugging tool like that could exist, and apparently, yes it can!

Anyway, great article!

Related:

https://www.serialice.com/index.html

https://github.com/coreboot/serialice