Siemens SL2-141-i ADSL2+ Router with WLAN. It is based on the RTA1025W from Dynalink, wich is out of production.

It is currently not possible to use OpenWRT on this device. The device wont't load a firmware, caused by a wrong boardname.

See also https://dev.openwrt.org/ticket/6920

system type             : RTA1025BW_16
processor               : 0
cpu model               : BCM6348 V0.7
BogoMIPS                : 239.20
wait instruction        : no
microsecond timers      : yes
tlb_entries             : 32
extra interrupt vector  : yes
hardware watchpoint     : no
VCED exceptions         : not available
VCEI exceptions         : not available

The pinout of the serial console port on the Sl2 is as follows

Serial connector (white, look at the pictures)
 ___
| 1 | -> Rx
| 2 | -> Tx
| 3 | -> GND
|_4_| -> +3,3V


 ___
|USB| For orientation...
|___|

The source code is hosted at alibstechnologies because they bought the Siemens broadband company.

Here's the source code.