[rcxdude]

Sure, but an RTOS doesn't help you much with safety critical guarantees. When you're worrying about that you're also worrying about redundancy of the hardware your software is running on, for example. The only thing that an RTOS is really helpful for is making it a bit easier to argue that some realtime guarantees can be met even if other code running on the device may have worst-case runtimes longer than your deadline (this doesn't really become a mitigation for a truly defective task, though, since at that point all bets are off unless you have some good task isolation). But this is not all embedded systems, not even all safety-critical ones, and there are other solutions available if you are not using an RTOS which can give you the same or better options in that case(like placing the critical code in a high-priority interrupt handler, for example).

[jacquesm]

If at all possible for such stuff I would use an FPGA and not software.

[imtringued]

The WLCSP Lattice FPGAs are waiting for you! Only 2€ a pop for 1k LUTs!