uclibc-ng/libc/sysdeps/linux/README

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

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