I've created a very basic FreeRTOS version for the SAMD20 (Cortex M0+). I took the Atmel Studio version and stripped out all unnecessary files.
I ended up modding some of the ASF files slightly, especially parts.h as without that, it brought up hundreds of warnings of processor re-definitions.
It has next to nothing in terms of peripheral set-up so far, but should be easy enough for people with knowledge of ASF to add the files in. They are in the zipped up directory structure.
Please note: THE CRYSTAL IS SET UP AS 16HMz as this is what I have on my hardware. Also, please note the project is called "wah", not FreeRTOSdemo.
There are three basic threads: two are included from the old main-blinky that just pass a value to a queue and read it in another queue; also, one which toggles a pin to prove I had the clocks set up and to test GPIO.
Hope this is of use to people and please point out any mistakes I have made. :~)