[coreboot] how to update firmware with tftp

[Amrish Purohit]

hi all,
i want help in following scenario.
as computer boot up with coreboot. it must wait for approximately 5 seconds
and listnen on tftp. if during that time if any firmware available than my
system will download that firmware and update with corrent one and that
system must boot with this new firmware. otherwise it will boot up with old
firmware.

i am using qemu. so is thre any idea for qemu with tftp
Amrish purohit