Hi Paul,
On Fri May 11, 2018 at 01:00:11 +0200, Paul Boddie wrote:
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).
It's option that available but on default most/all programs are static.
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!
You can set LD_DEBUG=1 in the environment of your program to make the dynamic loader tell you something. LD_TRACE_LOADED_OBJECTS=1 might also be of help. Add enviroment variable settings after the program's cmdline: ...:start({ ...}, "rom/myprog arg", { LD_DEBUG=1, ... });
Adam
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.