On the regulatory side, for networks the NERC Reliability Standards for the Bulk Electric Systems of North America address similar concerns (including cyber security) in electrical grids. For highly integrated systems MILS kernels are an engineering solution e.g. to keep actuators and monitoring subsystems apart.
Actually in Verisoft XT the successor of Verisoft now real C code is verified, including e.g. PikeOS with PowerPC assembly in a system developed to DO-178B airplane verification. In that project an important tool for C code verification is VCC developed by Microsoft Research, source included at that site.