[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.
http://cr.yp.to/daemontools/tai64n.html
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.
//Peter
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