cmc-labo/tinyos-rtos — reverse-engineered prompt

Build me a tiny embedded operating system in C for small IoT boards. I want it to be lightweight enough for microcontrollers but still feel complete, with a real task scheduler, priorities, timers, mutexes, semaphores, queues, event groups, and memory tracking.

It should include simple examples like blinking an LED, running multiple tasks, using event groups, an interactive serial shell, an IoT sensor demo, and MQTT messaging. I’d like the shell to have useful commands for checking tasks, memory, version, network stats, and basic control, with history and tab completion if possible.

Please make it build from a Makefile for ARM Cortex M by default, with options for Cortex M0, M7, RISC V, and AVR if practical. It should produce an ELF and binary in a build folder, and be runnable in QEMU for testing without hardware. Include clear docs and a quick start so someone can compile it, run an example, and flash it to a board.