[Haskell-cafe] How does the RTS "know" about ExitCode

Hi! I'm wondering how values stored in ExitCode "get to" the RTS (i.e. actually make the program exit with the given number). As far as I can tell ExitCode is used as an everyday normal-looking exception (which are defined entirely in "library code", by using the raise#/catch# primitives), without any direct link to the RTS. What am I missing? ====== Georgi