Okay, I forwardported the 4.1 netd to the 4.2 branch today, but it doesn't seem to work.
Source: here and here.
Source: here and here.
03-18 19:19:09.993: E/NetdConnector(404): NDC Command {19 softap set wlan0 AndroidAP wpa2-psk 42a3c33e94b4} took too long (912ms)
03-18 19:19:10.003: E/SoftapController(96): SIOCGIPRIV failed: -1
03-18 19:19:10.003: E/SoftapController(96): Softap startap - failed: -1
03-18 19:19:10.003: E/WifiStateMachine(404): Exception in softap start java.lang.IllegalStateException: command '20 softap startap' failed with '400 20 Softap operation failed (No such device)'
03-18 19:19:10.003: E/SoftapController(96): Softap already stopped
03-18 19:19:10.013: D/SoftapController(96): Softap fwReload - Ok
03-18 19:19:10.323: D/SoftapController(96): Softap fwReload - Ok
03-18 19:19:10.423: E/SoftapController(96): Softap set - failed: -1
03-18 19:19:10.433: E/WifiStateMachine(404): Exception in softap re-start java.lang.IllegalStateException: command '24 softap set wlan0 AndroidAP wpa2-psk 42a3c33e94b4' failed with '400 24 Softap operation failed (Operation not permitted)'