I have started working on a FreeRTOS port for TI BeagleBoard. The code is in a good state at the moment, so you may be interested in testing it on your beagleboard or even merge it to official FreeRTOS. The link to my git repo is the following
I have only tested it with the arm-none-eabi toolchain from http://www.codesourcery.com/. However, I don't expect different results with GCC toolchain.
The Makefile is adjusted to create different elf files for ARM and Thumb code ( rtosdemo-a and -t respectively ). I didn't have the time to test the serial demo, but it *should* work ( uses internal loopback for the Tx/Rx purposes ).
Feedback and patches are always welcomed :)
Update: Ignore the below comment ( Could someone please delete it as well? ). The file does not exist anymore. You can use the following git repository to build your own u-boot image for BeagleBoard ( Tested with BeagleBoard C4 + FreeRTOS )