Free, extremely simple and amazingly tiny real-time operating system (RTOS) designed for deeply embedded applications. Target: ARM Cortex-M family. It was inspired by the concept of a state machine.


  • kernel works in preemptive or cooperative mode
  • kernel can operate in tick-less mode (32-bit timer required)
  • signals (auto clearing, protected)
  • events
  • flags (one, all, accept, ignore)
  • barriers
  • semaphores (binary, limited, counting)
  • mutexes (recursive and priority inheritance)
  • fast mutexes (non-recursive and non-priority-inheritance)
  • condition variables
  • memory pools
  • message queues
  • mailbox queues
  • timers (one-shot, periodic)
  • cmsis-rtos api
  • c++ wrapper
  • all documentation is contained within the source files

StateOS Platforms

  • ARM

StateOS Components

  • None