how to open elf file image from inside genode? libbacktrace question

[ttcoder at netcourrier.com]

> > Your parent needs a ROMFile capability to run
> > your program. Ask it for that capability to read
> > your own file. You can call that RPC  getexecname
> > or whatever strikes your fancy.
> 
> the question is what path for open() call I should use for ROMfile?

Not sure if that's relevant to the discussion as I'm jumping in mid-stream, but in my Genode run 
scenarios I use the following, in order to access data files (not exe files) :

 	<start name="my_application"> 
		<config>
			<vfs>
				<rom name="background.jpeg"/>
   ..etc


And then I can use Genode's libc POSIX functions (open() or fopen() etc) with the above "files", as they 
are located at the very top root of the VFS, i.e. "/background.jpeg" (just prepended with a slash)

Cedric