1. libs for hardware

    stored in /lib/modules/<ver>

2. libs for apps

    stored in /usr/lib (e.g., /usr/lib/libbz.so.1

3. Building .a (ar)chive files with ar(1)

    The contents of an ar (/usr/lib/libbz.a) are the compiled object files .o
    List contents: ar t /usr/lib/libbz2.a
    Build:
        ar r libbz.a *.o
        ranlib libbz.a (or ar -s libbz.a)