The following files extend or replace some of the the newlib functionality: _startup.c: a customised startup sequence, written in C _exit.c: a customised exit() implementation _syscalls.c: local versions of the libnosys/librdimon code _sbrk.c: a custom _sbrk() to match the actual linker scripts assert.c: implementation for the asserion macros _cxx.cpp: local versions of some C++ support, to avoid references to large functions.