This directory contains library-description files.  Each _<libname>.mk_ file
contains the instructions for building the library _<libname>_. The .mk files
are never used directly but they are implicitely processed by the build
system.

Libraries implementing one interface may have specialized implementations for
different CPU architectures. Such architecture-specific _<libname>.mk_ files
are located in corresponding _spec/_ subdirectories. For example, the .mk
files of ARM-specific library variants reside in the _spec/arm/_ subdirectory.
The build system automatically finds the appropriate _<libname>.mk_ file by
evaluating the 'SPECS' build-configuration variable. Whenever the 'SPECS'
variable contains 'arm', the build system considers the _spec/arm/_ directory.
