Happy to announce that I was successfully able to adapt the Discovery_F4 
MP3 project to Atollic TrueSTUDIO ARM v6.0.0 Lite version which is a 
free professional quality toolchain based on GCC and Eclipse.

This project was inspired by the works of Benjamin Vedder 
[http://vedder.se/2012/12/stm32f4-discovery-usb-host-and-mp3-player/] 
and Marco W. [Beitrag "STM32F4 Discovery MP3 Player - komplett mit Code"]. I was able 
to enhance and port their work to CMSIS-RTX environment based on Open 
Sensor Platform framework. Details and sources can be found at: 
https://github.com/vermar/open-sensor-platform/tree/CMSIS-RTX/embedded/projects/Discovery_F4_MP3

Based on what Google is showing with some preliminary searching, this 
maybe the first project that provides a reference for CMSIS-RTX with GCC 
working on an STM32 device.

Cheers!

Okay