Binary File Descriptor library
The topic of this article may not meet Wikipedia's notability guidelines for products and services. (July 2011) |
Original author(s) | Cygnus Solutions |
---|---|
Repository | |
Written in | C |
Type | Library |
License | GNU General Public License |
The Binary File Descriptor library (BFD) is the GNU Project's main mechanism for the portable manipulation of object files in a variety of formats. As of 2003[update], it supports approximately 50 file formats for some 25 instruction set architectures.
History
When David Henkel-Wallace of Cygnus Support proposed developing the library as a way to open up new business opportunities for the company, Richard Stallman said that it would be difficult; David's response was that it wasn't such a "Big Fucking Deal". Abbreviated to "BFD", this became the library name.[1] "Binary File Descriptor" was invented later as a backronym for "BFD".
Design
BFD works by presenting a common abstract view of object files. An object file has a "header" with descriptive info; a variable number of "sections" that each has a name, some attributes, and a block of data; a
Internally, BFD translates the data from the abstract view into the details of the bit/byte layout required by the target
BFD[2] library can be logically divided into two parts. The front-end and the back-end. The front-end gives a common interface independent of underlying object file view. Users will be interacting with the object files with this interface. Even if the layout of the object files are not to known the user, user still be able to use the interface. This hiding of the detail is done with the help of the back-end. The back-end implements how the front-end interface interacts with the object files layout. Whenever a new object files type is introduced the back-end needs to register the type and implement it if it needs to be supported by the BFD application.
Although BFD was originally designed to be a generic library usable by a wide variety of tools, the frequent need to tinker with the API to accommodate new systems' capabilities has tended to limit its use;
The BFD library can be used to read the structured data out of a core dump.
BFD Library Usage
Eg: Print object file size using bfd library apis.
#include "bfd.h" #include <stdio.h> int main() { bfd* abfd = bfd_openr("a.o",NULL); printf("%llu\n", bfd_get_size(abfd)); return 0; }
Build command:
gcc main.c -lbfd -o output ./output # prints the size
References
- ^
"Open Sources: Voices from the Open Source Revolution". O'Reilly. January 1999. Retrieved 2011-11-11.
Gumby began designing the library and discussing the design with Stallman. Stallman said that the job was too difficult—it would require a complete rewrite of all the tools, and it would be too difficult to maintain. Gumby told him it wasn't such a "Big F*cking Deal" and hence named this new creation the BFD library. (We explained to our customers that BFD stood for the binary file descriptor library.)
- ^ [1]BFD specificaiton
- ^ Langasek, Steve (2005-05-22). "Re: depending on shared libbfd from binutils-dev". debian-devel (Mailing list). Retrieved 2011-04-03.
- ^ Kuratomi, Toshio (2010-06-04). "binutils once more". Fedora-packaging (Mailing list). Retrieved 2011-04-03.
- ^ Taylor, Ian (2003-09-12). "Re: FreeBSD 4.6 - binutils 2.14 installs useless libbfd". binutils (Mailing list). Retrieved 2011-04-03.