Re: FreeRTOS port for STM32F4
FreeRTOS will run on any Cortex-M device using GCC, Keil, IAR or Tasking compilers. I don’t think it is for the IDE to ‘support’ FreeRTOS as FreeRTOS builds with 18 different tool chains (not just Cortex) that I know of - although there are FreeRTOS kernel aware plug-in and more recently a configuration file editor plug-in that you can install.
As you have not said what the compiler error was there is no way I can assist you directly, but here are some links that might help, and if your issue is building FreeRTOS, rather than using the IDE, the FreeRTOS support forum might be a good place to ask the question.
http://www.freertos.org/Creating-a-new-FreeRTOS-project.html
http://www.freertos.org/porting-a-freertos-demo-to-different-hardware.html