Siemens Gigaset uses LGPL!
This caught me by surprise…
Your Gigaset S685/S675 IP’s firmware includes free software that is licensed under the GNU Lesser General Public License.
And there’s a link to the source code http://gigaset.siemens.com/shc/0,1935,hq_en_0_121785_rArNrNrNrN,00.html
Hmmm, now this might open up some possibilities… As it is LGPL, it indicates that there is probably some non-GPL code too, but it is very encouraging