The nanoBTS code is trying to find a struct gsm_bts based on
the ipaccess_gsmnet and the ipaccess_unit data. The pointer is
not initialized in the case of a sysmoBTS leading to a classic
NULL pointer dereference.
Move the feature init into the _init method. This way we can
re-use the start code of the nanoBTS. This ensures that the
ipaccess_gsmnet pointer is properly initialized and that the
signal handlers are installed.
so far, osmo-bts/sysmobts used to be entered as "sysmobts" type in the
configuration file. However, there are some differences in the
protocol/behaviour and we should reflect that by a new BTS plugin (with
lots of code reuse from the nanobts driver).
Harald Welte
Holger Hans Peter Freyther