On Sun, Aug 1, 2021 at 8:13 PM Andrew Warkentin <andreww591@gmail.com> wrote

To start the child the parent would either
> call exec() to start the child running a different program, or call a
> new function that starts the child with a parent-provided entry point
> and whatever memory mappings the parent set up.



> This is what I plan to do on the OS I'm writing
> (manipulating the child's state won't require any additional
> primitives beyond regular file I/O since literally all process state
> will have a file-based interface).
>

In that case you don't need *any* primitive except create_empty_process():
you can do exec() by opening the file, writing to /proc/<child>/mem and
then to <proc/<child>/pc-and-go.