rt-linux concept

FSMLabs rtlinux is based on a very small layer that is put beneath the actual Linux kernel. It is dropped in as a kernel patch and permits a system to utilize all the capabilities of a regular GNU/Linux desk-top system. Building these hard real-time capabilities as modules allows for runtime insertion, reducing the kernel changes to a minimum. This layer incorporates the following basic functionalities:

• interrupt interception ,no real interrupt ever reaches Linux, all interrupts destined for a non-rt task are flagged and passed to Linux when no rt-task is ready to run.
• timing precession in the nano-second range (rtl_time.o)
• scheduling of real time tasks independently of the Linux scheduler (rtl_sched.o), rtlinux is running a loadable scheduler beneath the non-rt level, this give great flexibility in design and optimization of the rt-scheduling policy.
• simple communications with the non-rt side via rtl_printk ,rt-fifos (rtl_fifo.o) and shared memory (mbuff.o).
• process synchronization via mutex and mmap functions (mutex.o mmap.o)
• runs Linux as its low-priority idle-task.