RT-Thread

RT-Thread
Developer	Bernard Xiong & RT-Thread Team
OS family	Real-time operating systems
Working state	Current
Source model	Open source
Latest release	4.0.2 / December 20, 2019; 5 years ago
Repository	github.com/RT-Thread/rt-thread ;
Marketing target	Embedded devices
Platforms	ARM (ARM7, ARM9, Cortex-M3, Cortex-R4, Cortex-M4, Cortex-A), AVR32, x86, M16C, NIOS, MIPS
Kernel type	Single Kernel
License	Apache 2.0
Official website	www.rt-thread.org

RT-Thread^[1]^[2] is an open source real-time operating system for embedded devices. It is distributed under the Apache 2.0+ licence. RT-Thread is developed by the RT-Thread Development Team based in China, after ten years' fully concentrated development. It is aimed to change the current situation in China that there is no well used open source real-time operating system in the microcontroller area.

RT-Thread kernel

Object-oriented real-time core (while remaining the elegant and flexible style of C programming panguage);
8, 32 or 256 priority scheduling multi-thread scheduling; Using the round-robin policy ensures that all threads having the same priority level will be scheduled equally;
Synchronization of threads: semaphore and mutual exclusion semaphore (mutex) to prevent priority inversion;
Complete and efficient support for communication between threads, including mailbox, message queues, event flag;
Static memory management supports thread suspend/resume when it allocates/frees a memory block and thread-safe dynamic heap management;
A device driver framework to provide standard interface to high level application;