The system contains a tool called mpt which allows to route some of the MSM modem traffic to the microUSB connection and such enables a passthru mode where the host PC could use the modem directly. That way the modem can be configured with some special software from Quallcom.
root@castle:/var/home/root# mpt Usage: To enable passthru: mpt [port_spec] To disable passthru: mpt disable (or mpt x) [port_spec] dun (or '0') : DUN (port0) only diag (or 'd') : Diag port only dun,diag (or '0d') : DUN (port0) and Diag port diag,gps : Diag port and GPS port userial : Serial passthru with USB cable serial : Serial passthru with Serial cable
Sadly a special USB driver is needed for this. It shows up like this on my linux box:
[16675.933683] usb 2-4.4: new full speed USB device using ohci_hcd and address 10 [16676.032663] usb 2-4.4: not running at top speed; connect to a high speed hub [16676.048665] usb 2-4.4: New USB device found, idVendor=0830, idProduct=8003 [16676.048675] usb 2-4.4: New USB device strings: Mfr=1, Product=2, SerialNumber=0 [16676.048682] usb 2-4.4: Product: Pre [16676.048686] usb 2-4.4: Manufacturer: Palm Inc. [16676.048876] usb 2-4.4: configuration #1 chosen from 1 choice