BFD is a package which allows applications to use the same routines to operate on object files whatever the object file format. A new object file format can be supported simply by creating a new BFD back end and adding it to the library.
BFD is split into two parts: the front end, and the back ends (one for each object file format).
- The front end of BFD provides the interface to the user. It manages memory and various canonical data structures. The front end also decides which back end to use and when to call back end routines.
- The back ends provide BFD its view of the real world. Each back end provides a set of calls which the BFD front end can use to maintain its canonical form. The back ends also may keep around information for their own use, for greater efficiency.
see also the online manual http://sourceware.org/binutils/docs/bfd/index.html
see also the wikipedia entry :http://en.wikipedia.org/wiki/Binary_File_Descriptor_library