I worked on interrupt system. I made it so that the context switching code is customizable with architectural specification. I also learned the atomic sequence of ISR, and established some outlines for overall interrupt system, based on what I learn.

I also thought of this "Kernel Service Device" that holds every kernel-provided services and unifies them into one interface. Basically, it's system call but bit more better and more organized. I really want everything to be unified into one "interface", not being scattered across the kernel.