I'm new to both ARM systems and Bluetooth, but have lots of Linux experience. I've been working with Pi4 as combination firewall/desktop replacement, there's an 8GB Pi4 on my desk, just received an A2 rated microSD, and I installed this 64 bit image with rpi-imager.

kali-linux-2021.3-rpi4-nexmon-arm64.img

The system is wired to my network, running hostapd and Pi-hole, providing a less insecure network for mobile devices. I enabled bluetooth and it does not see the Pi4 Bluetooth adapter. I disabled hostapd, restarted, and still this problem:

Code:
root@sandisk64:/var/log# systemctl status bluetooth
○ bluetooth.service - Bluetooth service
     Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: disabled)
     Active: inactive (dead)
       Docs: man:bluetoothd(8)


Oct 20 18:12:56 sandisk64 systemd[1]: Condition check resulted in Bluetooth service being skipped.


root@sandisk64:/var/log# grep "bluetooth" syslog
Oct 20 18:12:51 sandisk64 NetworkManager[470]: <info>  [1634753571.8823] Loaded device plugin: NMBluezManager (/usr/lib/aarch64-linux-gnu/NetworkManager/1.32.12/libnm-device-plugin-bluetooth.so)
I have a USB Bluetooth adapter, it's a CSR8510, I plug that into Pi4, works fine:

dmesg

Code:
[  188.517103] usb 1-1.1: new full-speed USB device number 5 using xhci_hcd
[  188.623240] usb 1-1.1: New USB device found, idVendor=0a12, idProduct=0001, bcdDevice=25.20
[  188.623271] usb 1-1.1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
[  188.623289] usb 1-1.1: Product: CSR8510 A10
[  188.700453] Bluetooth: Core ver 2.22
[  188.700535] NET: Registered protocol family 31
[  188.700544] Bluetooth: HCI device and connection manager initialized
[  188.700562] Bluetooth: HCI socket layer initialized
[  188.700575] Bluetooth: L2CAP socket layer initialized
[  188.700594] Bluetooth: SCO socket layer initialized
[  188.720507] usbcore: registered new interface driver btusb
[  188.878172] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[  188.878188] Bluetooth: BNEP filters: protocol multicast
[  188.878206] Bluetooth: BNEP socket layer initialized
[  188.906336] Bluetooth: RFCOMM TTY layer initialized
[  188.906363] Bluetooth: RFCOMM socket layer initialized
[  188.906382] Bluetooth: RFCOMM ver 1.11
[  188.909426] proc: Bad value for 'hidepid'
systemctl status bluetooth

Code:
● bluetooth.service - Bluetooth service
     Loaded: loaded (/lib/systemd/system/bluetooth.service; enabled; vendor preset: disabled)
     Active: active (running) since Wed 2021-10-20 18:16:10 UTC; 54s ago
       Docs: man:bluetoothd(8)
   Main PID: 1253 (bluetoothd)
     Status: "Running"
      Tasks: 1 (limit: 9300)
        CPU: 66ms
     CGroup: /system.slice/bluetooth.service
             └─1253 /usr/libexec/bluetooth/bluetoothd


Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.82 path=/MediaEndpoint/A2DPSink/sbc_xq_552
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.82 path=/MediaEndpoint/A2DPSource/sbc_xq_552
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.86 path=/MediaEndpoint/A2DPSink/sbc
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.86 path=/MediaEndpoint/A2DPSource/sbc
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.86 path=/MediaEndpoint/A2DPSink/sbc_xq_453
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.86 path=/MediaEndpoint/A2DPSource/sbc_xq_453
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.86 path=/MediaEndpoint/A2DPSink/sbc_xq_512
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.86 path=/MediaEndpoint/A2DPSource/sbc_xq_512
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.86 path=/MediaEndpoint/A2DPSink/sbc_xq_552
Oct 20 18:16:11 sandisk64 bluetoothd[1253]: Endpoint registered: sender=:1.86 path=/MediaEndpoint/A2DPSource/sbc_xq_552
I had a prior 32 bit image I was using and a spare microSD, so I installed this

kali-linux-2021.2-rpi4-nexmon.img

The prior 32 bit image similar problems. The onboard Bluetooth does not work, the USB adapter is recognized and behaves as expected. I have another Pi4 coming, so I'll be able to determine if it's a hardware problem. Anyone else seen this? Is there a patch for it?