  NOTE TO GITHUB USERS

This repository is no longer being updated on github.com, and will
soon be closed. Please visit the project home page to find a link to
its latest home:

  <http://www.muppetlabs.com/~breadbox/software/elfkickers.html>


This distribution is a collection of programs that are generally
unrelated, except in that they all deal with the ELF file format.

The main purpose of these programs is to be illustrative and
educational -- to help fellow programmers understand the ELF file
format and something of how it works under the Linux platform. For the
most part, these programs have limited real-world utility. (Although I
myself have found some of these programs quite useful while writing
the others.)

With the exception of shared use of the elfrw static library, each
program is independent of the others. There is no other shared code
between them, and they all take slightly different approaches to
handling ELF files.

The table of contents:

sstrip/
  sstrip is a small utility that removes as much as possible from an
  ELF file without affecting the file's memory image.

objres/
  objres is a simple utility that embeds arbitrary binary data files
  in object files as exported variables.

elfls/
  elfls is a utility that displays an ELF file's program and/or
  section header tables, which serve as a kind of global roadmap to
  the file's contents.

rebind/
  rebind is another small utility that alters the binding of selected
  exported symbols in an ELF object file.

elfrw/
  libelfrw.a is a small wrapper library. Its main purpose is to make
  32-bit ELF structures look like 64-bit structures when reading ELF
  files (and vice versa when writing them), thus allowing programs to
  more easily support both flavors of ELF files. The previous four
  programs all make use of this library.

elftoc/
  elftoc takes an ELF file and generates C code that defines a
  structure with the same memory image, using the structures and
  preprocessor symbols defined in your system's elf.h header file.

ebfc/
  ebfc is a compiler for a tiny programming language. The compiler can
  generate 64-bit ELF executables, object files, and shared libraries.

infect/
  infect provides a very simple example of modifying an ELF executable
  without affecting its original program.

See the README in each directory for more details about each program.

The ELF standard is worthwhile reading if you want to understand more
about the inner workings of these programs. You can find PDF documents
describing the 32-bit ELF standard, and the additions made for 64-bit
support, floating around in various unlikely places on the web. Search
engines are your friends here.

Many years ago I created a flat-text version of the document because
the Postscript version was too hard to search. You can find it at
<http://www.muppetlabs.com/~breadbox/software/ELF.txt>. Although it
only covers 32-bit ELF for x86, nearly all of it is still applicable
to 64-bit ELF files as well.

Earlier versions of this distribution also included my collection of
tiny ELF executables. I stopped including these because they are
somewhat orthogonal to the subject of most of the programs here. They
can be found at <http://www.muppetlabs.com/~breadbox/software/tiny/>
if you are curious about them.

    These programs are copyright (C) 1999, 2000, 2001, 2011, 2021 by
    Brian Raiter. These programs are free software; you can
    redistribute them and/or modify them under the terms of the GNU
    General Public License as published by the Free Software
    Foundation; either version 2 of the License, or (at your option)
    any later version. These programs are distributed in the hope that
    they will be useful, but WITHOUT ANY WARRANTY; without even the
    implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
    PURPOSE. See the GNU General Public License, included in this
    distribution in the file COPYING, for more details.

Bug reports and general feedback should be directed to the author at
<breadbox@muppetlabs.com>.

Share and enjoy.

Brian Raiter
<http://www.muppetlabs.com/~breadbox/software/elfkickers.html>
