I'm not sure I understand the question, but I interpret it as being about one of two things: Importing code written in a DSL into the OS at run-time, and creati

I'm not sure I understand the question, but I interpret it as being about one of two things: Importing code written in a DSL into the OS at run-time, and creating a custom OS kernel specified in a DSL at compile-time. There do exist examples of both, and there is some overlap between projects. Widespread examples include firewalls and routing rules written in DSLs, which get compiled into a form that gets run inside the kernel. Example: nftables in Linux. Some research OSes allow drivers to be written in a "safe" language to run inside the kernel. Some perform JIT-compilation, others create a custom kernel at compiled-time. Go search for Scout, Termite2, and Synthesis Kernel.