Hello everyone and best wishes for 2023 :) I have an old *Garmin Drive Smart 50 GPS* and I want to be able to attach it when it is in preboot mode to a VM hosted by a *Debian 11 host*. From what I understand, the preboot mode allows us to flash a firmware before the GPS actually starts (used among other things when the GPS is soft bricked). When I connect the GPS to the host it gives: |root@host:~# journalctl -kf|| ||# GPS in MTP storage mode (default when reset)|| ||...|| ||janv. 23 23:02:51 host kernel: usb 2-4: New USB device found, idVendor=091e, idProduct=48db, bcdDevice= 0.01|| ||janv. 23 23:02:51 host kernel: usb 2-4: New USB device strings: Mfr=1, Product=2, SerialNumber=5|| ||...|| ||# GPS in mass storage mode|| ||...|| ||janv. 23 23:01:29 host kernel: usb 2-4: New USB device found, idVendor=091e, idProduct=28db, bcdDevice= 5.09|| ||janv. 23 23:01:29 host kernel: usb 2-4: New USB device strings: Mfr=0, Product=0, SerialNumber=5|| ||...|| ||# GPS in preboot mode|| ||...|| ||janv. 23 23:09:05 host kernel: usb 2-4: New USB device found, idVendor=091e, idProduct=0003, bcdDevice= 0.01|| ||janv. 23 23:09:05 host kernel: usb 2-4: New USB device strings: Mfr=0, Product=0, SerialNumber=0|| ||janv. 23 23:09:13 host kernel: garmin_gps ttyUSB0: Garmin GPS usb/tty converter now disconnected from ttyUSB0| ... We see that *idVendor*, *idProduct*, *bcdDevice*, *Mfr*, *Product* and *SerialNumber* vary according to the modes.We also see that the GPS is seen as a *ttyUSB0* serial device. I managed to attach the GPS in preboot mode, thanks to a script which waits for the GPS to be detected in this mode (not detailed here so as not to overload, but I can publish it if necessary) and which attaches to a VM in running (*successfully tested on Debian 11 **and**Windows 7 guests*). Here is the code that generates the XML before attaching it : |...|| ||echo "<serial type='dev'> \|| || <source path='"$( \|| || ls -1 /dev/tty* | grep -Ev "tty(|S?[0-9]+)$" \|| || )"'/> \|| || <target type='usb-serial'> \|| || <vendor id='0x"$( \|| || echo 091e \|| || )"'/> \|| || <product id='0x"$( \|| || echo 28db \|| || )"'/> \|| || </target> \|| || </serial>" > serial_device.xml|| ||virsh attach-device vm-bullseye --file serial_device.xml &|| ||...| But once attached, this is what I see in the XML configuration of my VM (from *virt-manager*) : |<serial type="dev">|| || <source path="/dev/ttyUSB1"/>|| || <target type="usb-serial" port="1">|| || <model name="usb-serial"/>|| || </target>|| || <alias name="serial1"/>|| || <address type="usb" bus="0" port="4"/>|| ||</serial>| We see that libvirt has removed the *vendor/product id* from the XML. Also here is what I get from a *Debian 11 guest* : |root@vm-bullseye:~# journalctl -k -f|| ||...|| ||janv. 23 21:26:22 vm-bullseye kernel: usb 3-2: new full-speed USB device number 2 using uhci_hcd|| ||janv. 23 21:26:22 vm-bullseye kernel: usb 3-2: New USB device found, idVendor=0403, idProduct=6001, bcdDevice= 4.00|| ||janv. 23 21:26:22 vm-bullseye kernel: usb 3-2: New USB device strings: Mfr=1, Product=2, SerialNumber=4|| ||janv. 23 21:26:22 vm-bullseye kernel: usb 3-2: Product: QEMU USB SERIAL|| ||janv. 23 21:26:22 vm-bullseye kernel: usb 3-2: Manufacturer: QEMU|| ||janv. 23 21:26:22 vm-bullseye kernel: usb 3-2: SerialNumber: 1-0000:00:05.7-4|| ||janv. 23 21:26:22 vm-bullseye kernel: usbcore: registered new interface driver usbserial_generic|| ||janv. 23 21:26:22 vm-bullseye kernel: usbserial: USB Serial support registered for generic|| ||janv. 23 21:26:22 vm-bullseye kernel: usbcore: registered new interface driver ftdi_sio|| ||janv. 23 21:26:22 vm-bullseye kernel: usbserial: USB Serial support registered for FTDI USB Serial Device|| ||janv. 23 21:26:22 vm-bullseye kernel: ftdi_sio 3-2:1.0: FTDI USB Serial Device converter detected|| ||janv. 23 21:26:22 vm-bullseye kernel: usb 3-2: Detected FT232BM|| ||janv. 23 21:26:22 vm-bullseye kernel: usb 3-2: FTDI USB Serial Device converter now attached to ttyUSB0|| ||janv. 23 21:26:25 vm-bullseye kernel: usb 3-2: USB disconnect, device number 2|| ||janv. 23 21:26:25 vm-bullseye kernel: ftdi_sio ttyUSB0: FTDI USB Serial Device converter now disconnected from ttyUSB0|| ||janv. 23 21:26:25 vm-bullseye kernel: ftdi_sio 3-2:1.0: device disconnected|| ||...| The guest sees the GPS well but idVendor=*0403*, idProduct=*6001*, bcdDevice=4.00, Mfr=1, Product=2, SerialNumber=4 ... do not correspond to anything, and tools that expect GPS in preboot mode do not see it. My questions : Q1 : Is it possible ? Q2 : Am I doing it the right way ? Q3 : Is there a method to pass such a device directly (pass-through) ? Thank you in advance for the time you are going to devote to me :) With Adelphity, lnj