Hi Ruben,
thanks for pointing this out.
It has been known to use that Osmocom GSM/3G code doesn't work on big endian systems for quite some time. In the 10 year history of the project, I'm not aware of any user of our software on such systems, or anyone ever having requested support and/or contributed related patches.
As our [paid] development resources are still very limited compared to the vast scope of the 3GPP specs, protocols, network elements, etc. it has never been a priority, including now.
In the Osmocom project we are most happy to review and merge any related fixes! But in terms of sysmocom dedicating paid engineering time to fixing any of those: It's unlikely going to happen, sorry.
I still agree with other responders on this thread that it's useful to document known bugs in our bug tracker, though.
Regards, Harald