Hi Mark, On 11.8.2014 10:23, Mark Cave-Ayland wrote: > Hi all, > > It seems that a recent commit to OpenBIOS to increase the L11 timer > frequency from 10Hz to 100Hz (see > http://git.qemu.org/?p=openbios.git;a=commit;h=aad027388a5f0044781a95b184572ff0c38bbe37) > caused HelenOS boot to become extremely unreliable - it would tend to > hang most times at "Booting the kernel" instead of switching to the > splash screen and continuing to boot. > > With a bit of detective work, Artyom managed to trace it back to this > particular commit which simply increases the timer frequency from 10Hz > to 100Hz to match the OBP timer frequency. I'm wondering if maybe this > is because HelenOS gets confused if the L11 timer softint happens to be > asserted when booting the kernel which is considerably more likely with > an increase in timer frequency? > > I've just posted a patch to the OpenBIOS list to revert the frequency > increase at > http://www.openfirmware.info/pipermail/openbios/2014-August/008496.html > at the expense of the timer resolution but I thought it may be useful to > raise this here just in case it's caused by a bug somewhere in the > interrupt handling as none of Linux/FreeBSD/Solaris seem to have this > problem. > > FWIW another alternative solution could be for OpenBIOS to add timer > clearup functionality to SUNW,set-trap-table similar to OBP and so if > HelenOS were to call that method instead of directly altering %tba, then > it could become the responsibility of the PROM instead. Thoughts?
Thanks for this heads-up. I will have a look at this issue. Do you have an OpenBIOS binary which exhibits this behavior somewhere from where I could download it? There is a relatively long period of 'darkness' between the "Booting the kernel" message and the time HelenOS takes over the framebuffer. The best thing would be to use QEMU+gdb to see where exactly it hangs (or invisibly panics). Jakub _______________________________________________ HelenOS-devel mailing list [email protected] http://lists.modry.cz/listinfo/helenos-devel
