Debugging applications on Fiasco.OC. and questions about L4re

Adam Lackorzynski adam at
Mon Aug 30 20:12:02 CEST 2010


On Sun Aug 29, 2010 at 23:26:00 -0700, Pablo Montesinos wrote:
> I need to debug an application that I've ported to Fiasco.OC and I was
> wondering what is the preferred way to do it. (The application works
> fine in Linux, but there must be something wrong with the libraries I
> ported). Jdb seems not very friendly if all you want to do is
> debugging an application.

Indeed, a full-fledged local application debugger would be great to
have. Jdbs main features are state inspection and event tracing.
One way that definitely works is the classical printf-debugging. Also
very helpful are trace entries you can write with
fiasco_log_tbuf("text") and fiasco_log_tbuf_3val("text", 0, 1, 2)
(#include <l4/sys/ktrace.h>). You can see those when going to the
trace-buffer view in jdb using shift-T.

> My second question is about L4re. So far, all the applications running
> on my Fiasco.OC are console-based. However, I would like to run more
> complex apps that might require a graphical environment. I noticed
> that, with L4env, it was possible to have it. Is it possible to do it
> with L4re? Any plans to add it in the near future. I would use Genode,
> but I've been told at the Genode list that Fiasco.OC is not supported
> by Genode. Is there an alternative to Genode on L4re?

Graphics support is there, i.e. there are framebuffer abstractions,
windowing, input etc. You might want to look at the screenshot page to
get an idea.

Adam                 adam at

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