Spectacular Scheduler

Finally, we have some semblance of a userspace: a system call that does nothing other than print Test syscall, a template init_process for userspace processes hardcoded within the kernel that just invokes our test syscall in an infinite loop, and a round robin scheduler that just juggles around three copies of init_process forever.

Of course, no operating system should ever hardcode user processes in the kernel; instead, it should be able to read user programs from disk and launch them as processes. So that's what we're going to do next!