Hi,
I wrote a script that can be used on a host machine to read from the serial port and output timing information on each line received. It also tries to adjust for time spent by the target machine actually generating the serial reports. The script is attached if anyone wants to use it (it requires python and the pyserial package).
The results are interesting.
On my epia-cn machine, it takes coreboot-v2 8.7 seconds to launch SeaBIOS. It looks like about 4 seconds is lost due to a reboot half-way through the startup - I'm guessing a watchdog timer is kicking in. As to why it takes so long to boot - maybe rom caching is off?
SeaBIOS takes 1.5 seconds (from startup to OS launch) - after subtracting the 2.5 seconds spent waiting at the boot menu.
The biggest SeaBIOS time consumers:
500ms - initializing the ps2 port / keyboard
425ms - scanning for option roms
260ms - initializing ATA drives
200ms - running the via vga rom
-Kevin