Usb Modeswitch

Russell rreiter91-Re5JQEeQqe8AvxtiuMwx3w at
Tue Mar 18 12:52:11 UTC 2014

Hi I'll try to be a little more precise.

Yes that is the phone. I am connecting via usb tether. This phone predates wireless hotspot so if I want to use the phone as a modem I have to switch the mode from storage to modem

 The reason the device presents as storage is so that MS OS can copy the apps from the phone to the PC. These apps allow you to either copy files to and from the phone or 'eject' the block device so the character device may be mounted.

Oddly enough if I had installed linux with the phone tethered at that time, the character device would have been recognized. Udev is what calls usb_modeswitch from it's rules.d folder. Distros come with 40-android.rules as a part of udev and the generic rules default to storage class.

Newer devices simply switch the device class. However older units require that the id for vendor and product both be changed. Hex digits for vendor and  for product. Source switched to target. Then a message, just a string of numbers, is sent to the phone and voila, storage device is unmounted and no longer blocking access to the always on modem. At that point I can mount the node as TTY device.

Unfortunately currently only has one entry for motorola and that's for a different type of product.

Here's an example entry from the conf file, not for motorola tho.

DefaultVendor=  0x05c6
DefaultProduct= 0x1000
TargetVendor=   0x0af0
TargetProduct=  0x6901

Udevadm info --attribute walk (DEVPATH) gives me the defaults, but I'm trying to avoid having to do an install with the phone tethered in order to try and sniff out the target data.

I was hoping that someone on the list had done this grunt work already. Although now that I've tried to explain the issue it occurs to me that perhaps I can send 'eject' the storage device and then sniff out the serial attributes which would then be available.

If I can't find the target data on a net forum or from someone who has switched this older phone, I guess that's what I'll try next.


Scott Sullivan <scott-lxSQFCZeNF4 at> wrote:

>On 03/17/2014 01:21 PM, Russell wrote:
>> Hi, I'm trying to get an older Motorola phone -Snap XT300 to
>modeswitch. I'm able to use udevadm to find and mount the sim storage.
>What I am unable to find on the internet is the switch target id and
>message to send
> > What I am hoping is that someone on the list is using a motorola
>phone and can post a copy of target vendor and product id's and message
>contennt to enable the switch.
> >
> > Thanks
> > Russell
> >
>A fair bit more information would help us understand what your asking
>for Russell.
>After a quick search, do you mean this phone?
>What does 'modeswitch'ing do?
>I've seen it referenced in passing about older usb 3G modems, so I
>almost didn't missed that you were talking about a phone.
>How are you connecting to this phone, from your limited description I'm
>having to infer and guess that your connect it to a computer via USB?
>Is this correct?

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