Some Links to the RTEMS Source Tree

The RTEMS source tree is a little bit complex, as you might expect since it holds an entire OS for multiple APIs, CPUs and BSPs etc.

The tree is essentially split into two important subtrees

holds all the CPU independent pieces. Here are descriptions of the key directories with more links.
CPU (libcpu) and BSP (libbsp) support

There is more stuff under c/src:

Drivers for various chips.
A C++ API to RTEMS. Quite Useful. IMO, this should reside under cpukit...
This is not RTEMS networking but various contributed networking applications. Some of them are quick ports from UNIX and have caused name-clashing problems in the past. RTEMS networking is under cpukit/libnetworking