uclibc-ng/libc/sysdeps/linux

This directory level abstracts out the Linux Operating System dependent
features of uC-Libc for suported Linux architectures/CPUs. If you wanted to
port uC-Libc to some new Linux architecture (arm, mips, etc), this is the place
to add that support.

All the common stuff that is not at all dependent on a particular Linux architecture
goes in the 'common' directory.