For a libc on a weird OS I would recommend newlib (https://sourceware.org/newlib/ https://sourceware.org/newlib/), which is a libc for embedded systems and so h

For a libc on a weird OS I would recommend newlib (https://sourceware.org/newlib/ https://sourceware.org/newlib/), which is a libc for embedded systems and so has a well-defined way to implement the basic stuff that it needs to run.