- Download free RTOS source code from their website.
- Create new project in IAR IDE and select your micro STM32F3 in IDE.
- Create one main.C file in your project.
- Add all source file of free RTOS in your newly created project.
- Compile project.
In start there are so many error, but one by one solve out all error and you have your project working with free RTOS.
Simple....