L4Linux stop at "Calibrating delay loop ..."

Adam Lackorzynski adam at os.inf.tu-dresden.de
Tue Sep 20 00:29:19 CEST 2016


On Mon Sep 19, 2016 at 22:55:52 +0800, li94575 wrote:
>     I compiled the l4re-snapshot-2014092821 with the default modules.list, and everything seems goes
> well. However, L4Linux would stop at "Calibrating delay loop ...", because the value of jiffies did not change.
> Timer thread has not generate soft interrupt? If I entered jdb via ESC at this time, and quit via "g", then 
> l4linux can run again. It makes me confused so much.
>     Any help or suggestion will be very welcome.

This behavior typically indicates that there's an issue with Fiasco's
timer interrupt or with the user-level one in L4Linux.
For a start you could add e.g. a printk(".\n") in timer_thread in
arch/l4/kernel/timer.c to see if it really does something.
Does 'hello' work?
Although it's a bit of work you could also compare the code of your
snapshot and a recent one if there's any significant change (i.e. fix)
that might be relevant. Check arch/l4/kernel/timer.c
and src/kern/arm/timer-arm-generic.cpp and
src/kern/arm/generic_timer.cpp in the Fiasco kernel.

Adam                 adam at os.inf.tu-dresden.de
  Lackorzynski         http://os.inf.tu-dresden.de/~adam/

More information about the l4-hackers mailing list