Real Time Linux Courses
Real time programming can be considered as either Hard Real Time where it is an error if a deadline is missed or Soft Real Time where the distribution of response times is such that, occasionally, a deadline may be missed, but the system can still function as required. Linux systems configured with the PREEMPT-RT patches can exhibit good soft real time behaviour. Where the system has to satisfy certain hard real time constraints for some tasks, but not for others an approach using two co-existing kernels as with Xenomai 2, or Xenomai 3 Cobalt can be used. Xenomai 3 also supports a model based on a real time layer running natively over the mainline Linux kernel.
Real time behaviour can also be achieved, though this requires very careful analysis and design, on heterogenous multi-core processors such as those found in the BeagleBone Black which has two PRU (Programmable Realtime Unit) subsystems in addition to an ARM processor core, and the Beagle Board X15 which, apart from two ARM Cortex A15 cores comes with four PRU units, two DSP C66x DSP cores and two ARM Cortex M4 cores.