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. However, for new architectures which are
using the generic syscalls in the Linux Kernel, the 'common-generic'
directory should be used instead as they all use identical interfaces for
the system calls.