Content originally posted in LPCWare by TheFallGuy on Thu Jul 31 01:28:02 MST 2014
AFAIK, Crossworks uses GCC, so provided you use a GCC port of FreeRTOS it should build.
FreeRTOS doesn't know or need to know anything about the board - only the ARM core you are using. So use a Cortex-M4 port of FreeRTOS for the GCC toolchain.
If that doesn't help, ask on the FreeRTOS forums.