蓝牙

Resources

Wikipedia

这篇文章介绍了蓝牙控制器和蓝牙设备的配置和使用。

准备

本文假设 udev 和 USB 之前已经配置好。

安装

内核

In most cases enabling RFCOMM (CONFIG_BT_RFCOMM), HIDP (CONFIG_BT_HIDP), HCI USB (CONFIG_BT_HCIBTUSB) and/or HCI UART (CONFIG_BT_HCIUART) should be sufficient. The User-space I/O driver for HID input devices (CONFIG_UHID) should be enabled for Bluetooth keyboards and mice.

内核 启用蓝牙支持

[*] Networking support --->
      <M>   Bluetooth subsystem support --->
              [*]   Bluetooth Classic (BR/EDR) features
              <*>     RFCOMM protocol support
              [ ]       RFCOMM TTY support
              < >     BNEP protocol support
              [ ]       Multicast filter support
              [ ]       Protocol filter support
              <*>     HIDP protocol support
              [*]     Bluetooth High Speed (HS) features
              [*]   Bluetooth Low Energy (LE) features
                    Bluetooth device drivers --->
                      <M> HCI USB driver
                      <M> HCI UART driver
      <*>   RF switch subsystem support --->
    Device Drivers --->
          HID support --->
            <*>   User-space I/O driver support for HID subsystem

重要
Kernel may fail to initialize RFCOMM/BNEP being compiled as built-in. System log for bluetooth service in this case will mention the lack of RFCOMM/BNEP support. And this in turn for example may break HSP/HFP headset profile initialization. So if dmesg says nothing about RFCOMM, better recompile as a module.

固件

大多数蓝牙控制器需要 firmware 才能运行。如果 Linux 支持控制器，dmesg 通常会指示是否需要固件。sys-kernel/linux-firmware 软件包应提供所需的固件，尽管某些设备可能需要仅从制造商处才能获得的固件。

root #emerge --ask --noreplace sys-kernel/linux-firmware

USE 标记

BlueZ 是 Linux 蓝牙协议栈的实现，由 net-wireless/bluez 包提供。

USE flags for net-wireless/bluez Bluetooth Tools and System Daemons for Linux

btpclient	Enable BTP client
cups	Add support for CUPS (Common Unix Printing System)
debug	Enable extra debug codepaths, like asserts and extra output. If you want to get meaningful backtraces see https://wiki.gentoo.org/wiki/Project:Quality_Assurance/Backtraces
deprecated	Build deprecated plugins
doc	Add extra documentation (API, Javadoc, etc). It is recommended to enable per package instead of globally
experimental	Build experimental plugins
extra-tools	Install tools that upstream doesn't install on purpose by default. All this tools shouldn't be used. Then, please notify upstream about you still need them to let them know the situation.
mesh	Add support for Bluetooth Mesh control application and advertising bearer.
midi	Enable MIDI support
obex	Enable OBEX transfer support
readline	Enable support for libreadline, a GNU line-editing library that almost everyone wants
selinux	!!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur
systemd	Enable use of systemd-specific libraries and features like socket activation or session tracking
test	Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)
test-programs	Install tools for testing of various Bluetooth functions
udev	Enable virtual/udev integration (device discovery, power and storage device support, etc)

Data provided by the Gentoo Package Database · Last update: 2023-09-10 08:54 More information about USE flags

通过将 USE 变量设置为 bluetooth，可以在系统范围内启用蓝牙支持：

文件 /etc/portage/make.conf

USE="bluetooth"

Emerge

如果 USE 变量设置为 bluetooth，则系统需要更新：

root #emerge --ask --changed-use --deep @world

安装 BlueZ:

root #emerge --ask --noreplace net-wireless/bluez

配置

权限

Permissions for Bluetooth devices is handled automatically by D-Bus, and access is granted to all users by default.

服务

OpenRC

启动蓝牙：

root #rc-service bluetooth start

开机时启动蓝牙：

root #rc-update add bluetooth default

systemd

启动蓝牙：

root #systemctl start bluetooth

开机时启动蓝牙：

root #systemctl enable bluetooth

Enabling battery reporting

附注
The experimental USE flag needs to be enabled in net-wireless/bluez.

警告
Using bluezs experimental mode may prevent some bluetooth microphones from connecting automatically.

Bluez has a feature to report a devices battery level to upower. This feature is currently experimental and not stable. Enable experimental mode:

文件 /etc/bluetooth/main.conf

[General]
</div>

<div lang="en" dir="ltr" class="mw-content-ltr">
Experimental=true

Restart bluetooth to apply the configuration changes:

root #rc-service bluetooth restart

Now upower should know the battery level of every device which supports sending its own battery level.

使用

安装蓝牙控制器

显示控制器信息：

附注
hciconfig and other utilities are only available if net-wireless/bluez is installed with the deprecated USE flag enabled.

root #hciconfig -a

hci0:   Type: BR/EDR  Bus: USB
        BD Address: 00:02:72:2F:A9:33  ACL MTU: 1021:8  SCO MTU: 64:1
        UP RUNNING PSCAN 
        RX bytes:1166 acl:0 sco:0 events:43 errors:0
        TX bytes:960 acl:0 sco:0 commands:43 errors:0
        Features: 0xbf 0xfe 0xcf 0xfe 0xdb 0xff 0x7b 0x87
        Packet type: DM1 DM3 DM5 DH1 DH3 DH5 HV1 HV2 HV3 
        Link policy: RSWITCH SNIFF 
        Link mode: SLAVE ACCEPT 
        Name: 'BlueZ 5.21'
        Class: 0x000104
        Service Classes: Unspecified
        Device Class: Computer, Desktop workstation
        HCI Version: 4.0 (0x6)  Revision: 0x1000
        LMP Version: 4.0 (0x6)  Subversion: 0x220e
        Manufacturer: Broadcom Corporation (15)

Where hci0 is the name of the controller, and UP (3rd line) indicates that the controller is enabled.

Enable the controller if hciconfig indicates (with DOWN) (3rd line) that the controller is disabled:

root #hciconfig hci0 up

重要
When attempting to enable the controller, the following message may be displayed: Can't init device hci0: Operation not possible due to RF-kill

In this case, query the state of the Bluetooth radio transmitter with rfkill:

root #rfkill list bluetooth

0: hci0: Bluetooth
        Soft blocked: no
        Hard blocked: no

rfkill 可以与 net-wireless/rfkill 软件包或 >=sys-apps/util-linux-2.31 软件包一起安装。

附注
如果蓝牙在 BIOS/UEFI 中被阻止或禁用，rfkill 可能会错误地将控制器列为 Hard blocks: no。

如果 rfkill 指示（带有 Soft blocks: yes）控制器被阻止，则解锁控制器：

root #rfkill unblock bluetooth

如果 rfkill 指示（带有 Hard blocks: yes）控制器被阻塞，则通过物理开关或键盘功能键解锁控制器。

通过在 /etc/bluetooth/main.conf 中设置 AutoEnable=true 可以自动启用蓝牙控制器：

文件 /etc/bluetooth/main.conf

[Policy]
AutoEnable=true

In some instances Bluetooth controllers may have been soft-blocked by power management tools in udev. Make sure state is set to 1 in the corresponding rule file, or remove the following line entirely:

文件 /etc/udev/rules.d/10-local-powersave.rules

SUBSYSTEM=="rfkill", ATTR{type}=="bluetooth", ATTR{state}="1"

配对设备

Bluetooth devices need to be paired with a Bluetooth controller before they can be used. This is done by entering a PIN (or other code) on both devices via an interaction agent. Certain devices such as headsets do not allow entering an arbitrary PIN. These devices use a static PIN, which is usually 0000, 1111, 1234 or 9999. There are also devices (e.g. Sony BD Remote Control) that do not require PIN entry, and attempting to enter a PIN when prompted will result in failure. Pairing can be skipped with such devices.

This article only covers device pairing with bluetoothctl, which is a command-line interaction agent provided by the net-wireless/bluez package. If a graphical desktop environment is being used, device paring can be done with a graphical interaction agent. For KDE use kde-plasma/bluedevil, for GNOME use net-wireless/gnome-bluetooth, and for GTK use net-wireless/blueman or net-wireless/blueberry.

附注
Previously paired devices will need to be paired again when upgrading from BlueZ 4.

启动 bluetoothctl：

user $bluetoothctl

列出可用控制器：

[bluetooth]#list

显示一个控制器的信息：

[bluetooth]#show controller_mac_address

设置默认控制器：

[bluetooth]#select controller_mac_address

Power on the controller:

[bluetooth]#power on

Enable the agent and set it as default:

[bluetooth]#agent on

[bluetooth]#default-agent

Set the controller as discoverable (temporarily for 3 minutes) and pairable:

[bluetooth]#discoverable on

[bluetooth]#pairable on

扫描设备：

[bluetooth]#scan on

将设备置于配对模式。这一般涉及按下按钮或按钮组合，通常持续几秒钟。

发现设备 MAC 地址：

[bluetooth]#devices

与设备配对：

[bluetooth]#pair device_mac_address

按照提示输入 PIN：

[agent]PIN code: ####

In case the pin is not prompted but needed, this command may need to be added before pairing with the device (see this post):

[bluetooth]#agent NoInputNoOutput

如果被请求，允许服务授权：

[agent]Authorize service service_uuid (yes/no): yes

信任设备：

[bluetooth]#trust device_mac_address

连接设备：

[bluetooth]#connect device_mac_address

显示设备信息：

[bluetooth]#info device_mac_address

现在设备已经配对完成：

[bluetooth]#quit

hciconfig

Open and initialize HCI device:

root #hciconfig -a <hci0> up

Close HCI device:

root #hciconfig -a <hci0> down

Reset HCI device:

root #hciconfig -a <hci0> reset

Reset statistic counters:

root #hciconfig -a <hci0> rstat

Enable Authentication:

root #hciconfig -a <hci0> auth

Disable Authentication:

root #hciconfig -a <hci0> noauth

Enable Encryption:

root #hciconfig -a <hci0> encrypt

Disable Encryption:

root #hciconfig -a <hci0> noencrypt

Enable Page and Inquiry scan:

root #hciconfig -a <hci0> piscan

Disable scan:

root #hciconfig -a <hci0> noscan

Enable Inquiry scan:

root #hciconfig -a <hci0> iscan

Enable Page scan:

root #hciconfig -a <hci0> pscan

Get/Set default packet type:

root #hciconfig -a <hci0> ptype [type]

Get/Set default link mode:

root #hciconfig -a <hci0> lm [mode]

Get/Set default link policy:

root #hciconfig -a <hci0> lp [policy]

Get/Set local name:

root #hciconfig -a <hci0> name [name]

Get/Set class of device:

root #hciconfig -a <hci0> class [class]

Get/Set voice setting:

root #hciconfig -a <hci0> voice [voice]

Get/Set inquiry access code:

root #hciconfig -a <hci0> iac [iac]

Get/Set inquiry transmit power level:

root #hciconfig -a <hci0> nqtpl [level]

Get/Set inquiry mode:

root #hciconfig -a <hci0> inqmode [mode]

Get/Set inquiry data:

root #hciconfig -a <hci0> inqdata [data]

Get/Set inquiry scan type:

root #hciconfig -a <hci0> inqtype [type]

Get/Set inquiry scan window and interval:

root #hciconfig -a <hci0> inqparms [win:int]

Get/Set page scan window and interval:

root #hciconfig -a <hci0> pageparms [win:int]

Get/Set page timeout:

root #hciconfig -a <hci0> ageto [to]

Get/Set AFH mode:

root #hciconfig -a <hci0> afhmode [mode]

Get/Set Simple Pairing Mode:

root #hciconfig -a <hci0> sspmode [mode]

Set ACL MTU and number of packets:

root #hciconfig -a <hci0> clmtu <mtu:pkt>

Set SCO MTU and number of packets:

root #hciconfig -a <hci0> scomtu <mtu:pkt>

Delete link key from the device:

root #hciconfig -a <hci0> delkey <bdaddr>

Get local OOB data:

root #hciconfig -a <hci0> oobdata

Display supported commands:

root #hciconfig -a <hci0> commands

Display device features:

root #hciconfig -a <hci0> eatures

Display version information:

root #hciconfig -a <hci0> version

Display revision information:

root #hciconfig -a <hci0> revision

Add a device to the blacklist:

root #hciconfig -a <hci0> block <bdaddr>

Remove a device from the blacklist:

root #hciconfig -a <hci0> unblock <bdaddr>

Set LE Random Address:

root #hciconfig -a <hci0> lerandaddr <bdaddr>

Enable LE advertising:

root #hciconfig -a <hci0> leadv [type]

Show all commands device has support for:

root #hciconfig get commands

Disable Bluetooth

To disable Bluetooth at runtime, run the following command:

root #rfkill block bluetooth

To disable Bluetooth automatically on every boot, choose one of the following options:

Using udev to disable Bluetooth

When using UDEV, just install the following rule which will disable Bluetooth:

文件 /etc/udev/rules.d/80-disable-bluetooth.rules

SUBSYSTEM=="rfkill", ATTR{type}=="bluetooth", ATTR{state}="0"

Using OpenRC to disable Bluetooth

When using sys-apps/openrc, install the following script for local service and ensure it is executable:

文件 /etc/local.d/disable-bluetooth.start

#!/bin/sh
rfkill block bluetooth

root #chmod o+x /etc/local.d/disable-bluetooth.start

Disable Bluetooth at kernel level

When the kernel has modular Bluetooth support, disable loading of Bluetooth modules:

文件 /etc/modprobe.d/blacklist-bluetooth.conf

blacklist bnep
blacklist bluetooth
blacklist btusb

Troubleshoot

TLP and laptop_mode

If laptop-mode-tools is installed or TLP make sure they're not disabling Bluetooth to save power.

XBOX ONE controller pairing

It's a known issue that XBOX ONE wireless controllers will refuse to pair out of the box on most linux systems. To solve this issue ERTM needs to be disabled.

To disable it manually:

root #echo 'Y' > /sys/module/bluetooth/parameters/disable_ertm

This will disable ERTM only until the system is rebooted. To disable it permanently, install the xpadneo kernel module.

root #emerge --ask games-util/xpadneo

In most cases, this will automatically solve the issue. If it doesn't, add this line into xpadneo config manually:

文件 /etc/modprobe.d/xpadneo.conf

options bluetooth disable\_ertm=Y

Notebook has a Synopsys DesignWare Controller

Bluetooth support for this controller needs also these options in kernel config:

内核

Device Drivers  --->
    Character devices  --->
        Serial drivers  --->
            [*] 8250/16550 and compatible serial support
            [*] Support for Synopsys DesignWare 8250 quirks

Resolving firmware problems

It happens that the firmware of bluetooth adapters enters a state where it is unable to pair with a certain (or all) bluetooth devices. Resetting the adapter might solve such problems.

In the case of a laptop with a built-in bluetooth adapter this might be achieved by:

• Enter the laptop's firmware settings (BIOS) and disable the built-in adapter
• Save settings and restart the laptop
• Enter the firmware settings a second time and enable the bluetooth adapter again
• Save and restart
• Now try to pair the device again

另请参阅

• Bluetooth headset — describes the configuration of Bluetooth headsets within Gentoo Linux.
• Bluetooth input devices — describes the setup of Bluetooth input devices, for example a bluetooth mouse, on a Linux system.
• Bluetooth Network Aggregation Point — covers the setup of a Bluetooth Network Aggregation Point (NAP) on Gentoo Linux.
• Broadcom Bluetooth — details setup for Broadcom Bluetooth 4.x devices mostly based on BCM20702, BCM4354, and BCM4356 chipsets.

References