Durand’s Home Page

Embedding a file into an ELF binary

If you want to embed binary data (for example: images, keys, data) into your ELF executable and then use it from inside your application, this is what you do:NB: This example may crash because I’m printing the string which may or may not have a terminating NULL character. You should see the beginning of the file anyway.

Create your data file:

	 README.TXT:

		This is a readme file.

Turn it into an object file:

	   objcopy -I binary -O elf32-i386 \
	            --redefine-sym _binary_README_TXT_start=_README \
	            --redefine-sym _binary_README_TXT_end=_README_END \
	            --redefine-sym _binary_README_TXT_size=_README_SIZE \
		    README.TXT README.o

Verify that it is the correct format: (objcopy messes up sometimes)

	  objdump -t README.o

	  -- README.o:     file format elf32-i386

If it comes out as a elf32-little, you need to change the byte at 0×12 to a 3:

	   echo -e "\3" | dd seek=18 bs=1 count=1  conv=notrunc of=./README.o

.. check again

Create your application:

	 main.cpp
		#include <stdio.h>

		extern char* _README;

		int main(int argc, char *argv[] )
		{
	        	printf("%s\n", &_README);
		        return 0;
		}

Compile it all together:

	  g++ -Xlinker README.o main.cpp   -o test

Run it:

	  ./test

all done.