[Unit]
Description=Start bluetooth on ttyS0
After=systemd-modules-load.service

[Service]
Type=forking
ExecStart=/bin/bash -c 'echo 0 > /sys/class/rfkill/rfkill0/state; sleep 1; echo 1 > /sys/class/rfkill/rfkill0/state; sleep 1; exec /usr/bin/hciattach /dev/ttyS0 bcm43xx 1500000 flow nosleep'

[Install]
WantedBy=multi-user.target