Following instructions on https://github.com/beagleboard/kernel/tree/3.8-rt, I’ve compiled the branch 3.8-rt with PREEMPT_RT on .config and the kernel won’t boot.
Console output: http://pastebin.com/L88zJ0BL
Removing PREEMPT_RT from .config allows kernel to boot.
Anyone successfully booted an 3.8 kernel with PREEMPT_RT?
The OSADL folks have an AM335x -rt kernel, but it's not for a BeagleBone:
The PREEMPT_RT on ARM still seems pretty raw, and the performance
doesn't seem to be quite there yet.
I'm using xenomai for real-time on the BeagleBone to run LinuxCNC, and
there's an automated build script available (based on RCN's kernel
builds) if you want to make your own kernel:
...the required xenomai patches are in the official git tree, and will
be part of the next official release.
Using xenomai isn't transparent. For jack, you'll have to use preempt_rt.