bfd_init_window
...............

 -- Function: void bfd_init_window (bfd_window *);
     Initialise mmap window.

bfd_free_window
...............

 -- Function: void bfd_free_window (bfd_window *);
     Finalise mmap window struct.

bfd_get_file_window
...................

 -- Function: bool bfd_get_file_window (bfd *, file_ptr, bfd_size_type, bfd_window *, bool *writable*);
     mmap from a bfd's iostream.