BlueZ is a Bluetooth stack for Linux kernel-based family of operating systems. Its goal is to program an implementation of the Bluetooth wireless standards specifications for Linux. As of 2006, the BlueZ stack supports all core Bluetooth protocols and layers.[2] It was initially developed by Qualcomm, and is available for Linux kernel versions 2.4.6 and up. In addition to the basic stack, the bluez-utils and bluez-firmware packages contain low level utilities such as dfutool which can interrogate the Bluetooth adapter chipset to determine whether its firmware can be upgraded. Wikipedia
Components
HCI Core
HCI UART, USB and Virtual HCI device drivers
L2CAP module
Configuration and testing utilities
Bluez Service
root@edison:~#systemctlstatusbluetooth●bluetooth.service-BluetoothserviceLoaded:loaded (/lib/systemd/system/bluetooth.service; enabled)Active:active (running) since Sat 2016-07-16 16:56:29 UTC; 50minagoDocs:man:bluetoothd(8)MainPID:202 (bluetoothd)Status:"Running"CGroup:/system.slice/bluetooth.service└─202/usr/lib/bluez5/bluetooth/bluetoothd-EJul1616:59:39edisonbluetoothd[202]:ErroraddingLinkLossserviceJul1616:59:39edisonbluetoothd[202]:Notenoughfreehandlestoregister...eJul1616:59:39edisonbluetoothd[202]:Notenoughfreehandlestoregister...eJul1616:59:39edisonbluetoothd[202]:Notenoughfreehandlestoregister...eJul1616:59:39edisonbluetoothd[202]:CurrentTimeServicecouldnotbere...dJul1616:59:39edisonbluetoothd[202]:gatt-time-server:Input/outputerror (5)Jul1616:59:39edisonbluetoothd[202]:Notenoughfreehandlestoregister...eJul1616:59:39edisonbluetoothd[202]:Notenoughfreehandlestoregister...eJul1616:59:39edisonbluetoothd[202]:Failedtoreadadvertisingfeatures:...)Jul1616:59:39edisonbluetoothd[202]:hci0LoadConnectionParametersfail...)Hint:Somelineswereellipsized,use-ltoshowinfull.root@edison:~#