Building programs with MODE=shared in L4Re

[Paul Boddie]

Hello,

I have been busy writing libraries and programs for L4Re and recently had to 
think about the size of the payloads I have been deploying. It appears that in 
the build system, one can use MODE=shared to build dynamically-linked 
programs, and there is a shared version of the hello example in the examples 
package.

However, I don't see any recipe for doing this for other programs. My 
impression is that the dynamic linker must have all the required libraries 
deployed as modules, and so I wrote a script to generate a list of such 
modules using readelf. In addition, it appears that libl4sys-direct.so is 
required (which readelf does not detect).

Adding these modules to my conf/modules.list should yield success, but within 
my constrained debugging environment, I only see that "shared" programs fail 
to start. I really need to see if they start but then experience some 
initialisation problem, or whether they actually crash but Mag keeps their 
viewports around.

Are there any other things that I need to consider when building and deploying 
such programs? I searched for guidance on this topic and only found the 
following:

http://os.inf.tu-dresden.de/pipermail/l4-hackers/2014/007094.html
http://os.inf.tu-dresden.de/pipermail/l4-hackers/2016/007830.html

Both of these discussion threads only provide some details and are obviously 
not tutorials.

Thanks for any clues you might be able to provide!

Paul

P.S. I guess I could also see if the CI20 produces useful console-level 
details, perhaps indicating an architecture-related problem. Usually, however, 
the problem is caused by some simple mistake I have made, so I suspect that 
there is merely some detail I have forgotten.