FreeRTOS

The free FreeRTOS is a reliable, open source real-time operating System FreeRTOS for embedded systems system and RTOS market leader for microcontroller and small microprocessors. It is optimized for embedded usage and provides basic functionalities for scheduling, memory management and inter-task communications. It is based on a microkernel architecture. Thus said, a microkernel architecture and therefore provides mechanisms like low-level address space management, task management, inter-process communication and the applications can access the hardware more or less independent of the kernel. FreeRTOS is a scalable real-time kernel designed specifically for small embedded systems. Besides that, it is open source with GPL and royality-free, it has features like:

• FreeRTOS scheduler - preemptive, cooperative and hybrid configuration options, with optional time slicing.
• RTOS objects (tasks, queues, semaphores, software timers, mutexes and event groups) can be created using either dynamically or statically allocated RAM.
• FreeRTOS-MPU supports the ARM Cortex-M3 Memory Protection Unit (MPU).
• Designed to be small, simple, and easy to use. Typically, a RTOS kernel binary image will be in the region of 4K to 9K bytes.
• Mutexes with priority inheritance.
• Efficient software timers.
• Powerful execution trace functionality.
• Stack overflow detection options.