I did manage to get it running again with a new provided Debian DUSUN image (DSGW-210-Debian_image_RV1.3.5) - despite no LEDs working and the “AndroidTool” output being somewhat ambiguous, “just flashing” into the blind seemed to have worked.
But, now I have an old problem again with the BLE state - I had a solution for the older compiled image/kernel, but the script does not seem to work properly for the newer version that I got now:
After running this:
./bflash -d /dev/ttyUSB0 -b 500000 -f /tmp/bt_rcp-BG21_768_OK_32_conn.gbl
hciattach /dev/ttyUSB0 any 115200 noflow
at least hciconfig -a finally shows an adapter, but the mac-address is still 00:00:00:00... and hciconfig hci0 up runs into a timeout.
Do you have updated docs and scripts for the new Debian version, or a working link for the older image (I think 1.2.4?)