Seems there is a case or two of possible infinite while() loops within the uart8250 serial console code. This is a wild guess, but the uart
Yeah I dont like that too. Maybe worth to do a timeout? Or Loop count? It is always better to boot than to have perfect serial output ;)
But in this case I would think memory is not 100% OK. Worth to check if 1M->3M is OK (this is where coreboot ramstage goes)
Thanks Rudolf