pi@tv:~ $ apt-cache show pi-bluetooth
Package: pi-bluetooth
Version: 0.1.1
Architecture: armhf
Maintainer: Serge Schneider <serge@raspberrypi.org>
Installed-Size: 41
Depends: init-system-helpers (>= 1.18~), bluez, bluez-firmware
Homepage: https://github.com/RPi-Distro/rpi-bluetooth
Priority: optional
Section: misc
Filename: pool/main/p/pi-bluetooth/pi-bluetooth_0.1.1_armhf.deb
Size: 3240
SHA256: 693ff548b9c9b7b2461b4db97bdb6db54858ee8bfefdbfd405d402acb272f2ac
SHA1: 6904d8c719fb6e4bed41346fe15e19c1b16c3514
MD5sum: 086d06bd5681085c2ac374fce0665e87
Description: Raspberry Pi 3 bluetooth
 Loads BCM43430A1 firmware on boot
Description-md5: 969edfa3554f6f3cd1ddaca2226fe3a8

pi@tv:~ $ dpkg -L pi-bluetooth
/.
/lib
/lib/systemd
/lib/systemd/system
/lib/systemd/system/hciuart.service
/usr
/usr/share
/usr/share/doc
/usr/share/doc/pi-bluetooth
/usr/share/doc/pi-bluetooth/copyright
/usr/share/doc/pi-bluetooth/changelog.gz
pi@tv:~ $ cat /lib/systemd/system/hciuart.service
[Unit]
Description=Configure Bluetooth Modems connected by UART
ConditionPathIsDirectory=/proc/device-tree/soc/gpio@7e200000/bt_pins
Before=bluetooth.service
After=dev-serial1.device

[Service]
Type=forking
ExecStart=/usr/bin/hciattach /dev/serial1 bcm43xx 921600 noflow -

[Install]
WantedBy=multi-user.target
pi@tv:~ $