This variable attribute informs the compiler that a static variable is to be retained in the object file, even if it is unreferenced.
Static variables marked as used are emitted to a single section,
in the order they are declared. You can specify the section that
variables are placed in using
Data marked with
tagged in the object file to avoid removal by linker unused section
This variable attribute is a GNU compiler extension that the ARM compiler supports.
Static functions can also be marked as used using