coreboot-4.5-1079-g613350897d Fri Feb 24 14:59:42 UTC 2017 romstage starting...
Julius, do you have any measurements, how much time printing 100 characters over the serial console would take?
Back of the envelope calculation for normal 115200 baud says
1000ms * 100 chars * 9 bits per char (with parity) / 115200 bps = 8ms
Certainly not the end of the world, but I just don't like unnecessary inefficiency even if it's small. I also feel like it should be a reasonable use case to say "I want *only* warnings/errors" (e.g. so you can pipe them directly into some firmware error log or something), but maybe that's just me.
Also, does that really matter for production systems? What log level are they normally shipped with?
If you're talking about Chrome OS production systems, we just set BIOS_SPEW but disable the UART, so from that point I don't care either way.