PIC18 Port : anybody tried with USB f-w?

Hello Forum, I’ve been looking at FreeRTOS and now plan to use it with PIC18F4550 as well as incorporating USB interface (with Microchip supplied USB FS Framework). What would be the preferred way to ‘link’ (not in linker meaning – I mean rather ‘connect’) the two pieces together, so that FreeRTOS tasks can either receive or send USB transmission (take the HID as example – interrupt transfer mode)? I think it culd be enough just to : - create a USB xmit task - another task being a ‘HAL’ (this and the above is more-or-less what the Microchip framework does – only as single minded program (no OS) - the user tasks never use the USB xmit directly - user tasks to HAL, and HAL to xmit connect with queues So, efectively, having a layered model, the Microchip framework serving as a ‘driver’. Did anybody do something like this ever (use FreeRTOS and USB framework along each other)? I wish to do it under Microchip MPLAB IDE 8.10, MPLAB C18, MCHPFSUSB 2.1.