RT-Thread RTOS is an open source operating system comes from China. It has very small core (minimal configuration is only 2.5KB ROM, 1KB RAM usage), using a priority-based pre-emptive scheduling and safe with deeply real-time operating system:
- The small footprint, focus on microcontrollers (especially for ARM Cortex-M0/M3).
- Object oriented design in C programming language
- Unlimited number of threads and round-bin scheduling is used for same priority threads
- Support nested interrupt.
- Easy to configure by header source file.
- Commercial friendly license.
In addition, there are several components upon RT-Thread RTOS. The finsh shell is a command shell which can accept command like C programming language expression; The device file system is a supper file system like virtual file system and can contain several concrete file system such as FAT, NFSv3 and ROMFS. The RT-Thread/GUI is a multi-thread and multi-window graphic user interface, which provides GBK Chinese display, rich drawing routines and widgets, such as label, button, checkbox, radio box, textbox, tab controller, progress bar, slider etc.