[coreboot] Timing via serial port

Peter Stuge peter at stuge.se
Sun Apr 19 04:05:41 CEST 2009

Kevin O'Connor wrote:
> 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.

After stty I've used tai64n for this. I then wrote taidelta to show
the time difference between tai64n output lines.


No web for taidelta yet, but I'll give out source.

> 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).

I like that it's very simple!

Kevin O'Connor wrote:
> Nope - looks like calibrate_tsc is taking 2.9 seconds to calibrate:

Look for a really long option with TSC in the name. It's set for
epia-m. We added it in Hamburg to control how to initialize timers.
I think you're getting the slower method.


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