If you look at the FreeRTOS distribution, there is two PPC ports done for FPGAs.
S32DS comes with FreeRTOS ports for a bunch of larger MPC57xx devices.
ST's development suite has FreeRTOS ports for multiple processors in the SPC5xx family which are the same chips as the MPC5XXX ones.
Between those three sources, I was able to put together a working port for the '5634M. Be ready to write some assembly code.
Andrei
