SYNOPSIS

       re [ options ] <executable file> <symbol file>

DESCRIPTION

       re  is the resource editor.  The resource editor is a tool
       that takes as input an ELF executable binary file,  and  a
       generic  binary  file,  and  generates as output a new ELF
       executable with one of it's resources replaced by the  new
       binary  file.  The executable must have had it's resources
       compiled using rc, the symbol table must be  present  (the
       executable  must  not be stripped), and in most cases must
       have been linked with the -q or  --emit-relocs  option  on
       the ld linker.

       A  resource  is  a  pair of symbols (variables) in an exe­
       cutable or relocatable object file. The first symbol is an
       array  of  bytes containing data the program uses, and the
       second is an integer containing the size of the first sym­
       bol.  Resources  provide  a  method of easily using binary
       data within C programs, and of flexibly changing this data
       after compilation.

       The  name of the symbols are determined by the input file­
       name, unless the -s ot -l options  are  used.   The  first
       symbol  (the data variable, known as the `data symbol') is
       named the same as the file, less the path  and  everything
       past  the  first  `.'.  The  second  symbol  (known as the
       `length symbol') is named the  same  as  the  first,  with
       `_len' appended.

       re  often  requires  the ELF executable it is modifying to
       contain the relocation sections which were used when link­
       ing  to  resolve  symbol references in the original object
       files. This is only required if the new resource is larger
       than  the old resource.  The reason for this is that since
       the new resource is larger, any symbols or sections  after
       the  symbol  in  the  ELF  executable  will  have  changed
       address/offset,  and  so  their  references  in  the  code
       (.text, .init, .plt) must be updated.

       If  the new resource is smaller or equal size, the reloca­
       tions section is not needed; the old resource is overwrit­
       ten,  and padded with 0's if smaller, so that the resource
       takes up the same size as before in the file.  Of  course,
       the  resource  length  variable  is updated to the correct
       size so the executable runs as expected.

OPTIONS

       -d     Show debugging information

       -h     Show help
       cutable file is saved as `new':

          $ re -o new old icon.png

       This next example does the same as above, but changes  the
       symbols `img' and `imgLen' in old:

          $ re -o new -s img -l imgLen old icon.png

AUTHOR

       Written by Jeff Williams <minimalism@somaradio.ca>

REPORTING BUGS

       Report bugs to <minimalism@somaradio.ca>.

SEE ALSO

       rc(1),  gcc(1), ld(1), objcopy(1), objdump(1), readelf(1),
       and elf(5).




Jeff Williams                  0.03                         re(1)