skaiui2/SKRTOS_sparrow ? reverse-engineered prompt

Build me a modular real time operating system microkernel in C for embedded systems.

I want it organized so the core kernel is easy to understand and teach, with separate pieces for hardware porting, board support, common data structures, networking, and a file system layer. Please include clear documentation and tutorial style explanations so someone can learn how the kernel works step by step, not just use it.

The kernel should support multiple scheduling styles, including a simple learning friendly version for small task counts, a more complete linked list based version, a red black tree based version for heavier workloads, and an experimental EDF style version aimed at predictable periodic tasks. Make the code clean and modular, with comments where they help explain the design. If you need to check current embedded C or RTOS practices online, go ahead.