Generating readable C code was an important goal from early on. Parts of the linux kernel would have to be translated to Low*, which is the subset of F*, that can be extracted to C.
I guess there would be a new build step, that runs when code is checked in, to not burden everyone with all the new toolchain (F*, z3, karamel, maybe OCaml and more). While the generated C code can be read and understood by C programmers, changes to that part should be done in Low* and that may require changes to proofs in F* or to the extraction tool (karamel). That's a pretty big investment for a project like linux and I guess, any work in that direction will happen on forks for a while, before there is enough confidence that such changes are sustainable.
A good first candidate may be HACL* (https://hacl-star.github.io), a cryptographic library that is already used in several projects.
I guess there would be a new build step, that runs when code is checked in, to not burden everyone with all the new toolchain (F*, z3, karamel, maybe OCaml and more). While the generated C code can be read and understood by C programmers, changes to that part should be done in Low* and that may require changes to proofs in F* or to the extraction tool (karamel). That's a pretty big investment for a project like linux and I guess, any work in that direction will happen on forks for a while, before there is enough confidence that such changes are sustainable.
A good first candidate may be HACL* (https://hacl-star.github.io), a cryptographic library that is already used in several projects.