[Ubuntu] Bluetooth module not found

Ubuntu Bluetooth module

https://ubuntu.pkgs.org/20.04/ubuntu-universe-arm64/bluetooth_5.53-0ubuntu3_all.deb.html => 깔아도 똑같이 dmseg에 뜨지 않는다

• blueman 설치

sudo apt install blueman
sudo apt install bluez bluez-obexd

• blueman-manager 실행 시 에러 발생

blueman-manager version 2.1.2 starting
blueman-manager 23.05.51 ERROR    Manager:118 on_dbus_name_appeared: Default adapter not found, trying first available.
blueman-manager 23.05.51 ERROR    Manager:122 on_dbus_name_appeared: No adapter(s) found, exiting

• sudo dmesg 확인시 ERROR발견

[  764.275596] Bluetooth: hci0: RTL: examining hci_ver=0a hci_rev=000b lmp_ver=0a lmp_subver=8761
[  764.276657] Bluetooth: hci0: RTL: rom_version status=0 version=1
[  764.276668] Bluetooth: hci0: RTL: loading rtl_bt/rtl8761bu_fw.bin
[  764.276719] bluetooth hci0: Direct firmware load for rtl_bt/rtl8761bu_fw.bin failed with error -2
[  764.276726] Bluetooth: hci0: RTL: firmware file rtl_bt/rtl8761bu_fw.bin not found

• Install

$ cd /usr/lib/firmware/rtl_bt
$ sudo ln -s rtl8761b_fw.bin rtl8761bu_fw.bin

• 재시작 하면! 됨