How big is RTEMS?

[Michael Silva]

Pardon me for asking such a basic question, but I couldn't find any  
data on the RTEMS site.  I think RTEMS may be just the OS I'm looking  
for but I'd like to get some idea of its memory requirements.  Is  
there any sort of matrix listing code size for various  
configurations, from a bare-bones tasking kernel on up?  My  
particular focus is ARM7 at the moment, and I want to get an idea how  
small/cheap I can go in that family.  Thanks.