Last week, Paolo Bonzini of Red Hat announced qboot, a new x86 firmware option for QEMU. qboot is a minimal x86 firmware that runs on QEMU and, together with a slimmed-down QEMU configuration, boots a virtual machine in 40 milliseconds on an Ivy Bridge Core i7 processor. The code is 8KB in size.

More information:
git://github.com/bonzini/qboot.git
https://lwn.net/Articles/645455/

https://www.kraxel.org/repos/firmware.repo
https://www.kraxel.org/repos/jenkins/qboot/