Piccolo OS: A Tiny, Educational Multitasking OS for Raspberry Pi Pico

Piccolo OS is a small multitasking operating system designed for the Raspberry Pi Pico, primarily as a teaching tool. It demonstrates the fundamentals of a cooperative multitasking OS and the Arm Cortex-M0+ architecture. Tasks are scheduled in a simple round-robin fashion, using MSP and PSP stack pointers for context switching and transitioning between Thread and Handler modes. While simplified in functionality, it clearly illustrates core multitasking OS principles, making it ideal for learning about operating system internals.