This is the first part of the NetBSD install booted from the USB stick, that I captured with a serial console:
Code:
Welcome to the NetBSD/amd64 7.0 installation image
===============================================================================
ACPI (Advanced Configuration and Power Interface) should work on all modern
and legacy hardware. However if you do encounter a problem while booting,
try disabling it and report a bug at http://www.NetBSD.org/.
1. Install NetBSD
2. Install NetBSD (no ACPI)
3. Install NetBSD (no ACPI, no SMP)
4. Drop to boot prompt
Choose an option; RETURN for default; SPACE to stop countdown.
Option 1 will be chosen in 06seconds..
14186104+654328+594952\[1024968+717517]=0x1163068
Unfortunately documentation of NetBSD serial console configuration is hard to find.