objcopy prepends directory pathname to symbol name

Question

I am tying to use objcopy to include a binary form of a text file into an executable. (At runtime I need the file as a string). This works fine until the linker

Answer 1

Generic method of including raw data into ELF is supported by .incbin assembler directive.

The trick is to create template .S file that could look like this:

        .global foo_start
foo_start:
        .incbin "foo.raw"

        .global foo_end
foo_end:    

This file is preprocessed via cpp so we don't have to hardcode file name there, eg. we can write:

        .incbin __raw_file_path__

... and then pass it while compiling:

gcc -D__raw_file_path__='"data/foo.png"' foo.S -c -o data/foo.o

Lastly, as we prepare .S file ourself we can add some extra data and/or information. If you include raw "text files" and want these to be available as C strings you can add '0' byte just after raw data:

        .global foo_start
foo_start:
        .incbin "foo.raw"

        .global foo_end
foo_end:    
        .byte 0

        .global foo_size
foo_size:
        .int foo_end - foo_start

If you want full-blown flexibility, you can of course pre-process file manually to alter any part of it, eg.

.global @sym@_start
@sym@_start:
       .incbin "@file@"
       .global @sym@_end
@sym@_end:

... and then compile it:

sed -e "s,@sym@,passwd,g" -e "s,@file@,/etc/passwd,"