Usb Modeswitch - Update

Russell Reiter rreiter91-Re5JQEeQqe8AvxtiuMwx3w at
Wed Mar 26 23:37:26 UTC 2014

I thought I'd update this in case anyone else is working with an older
phone with a crippled rom. Apparently this phone didn't allow for
tethering for an Internet connection. Although the hardware is
present, the rom doesn't address it.

After I grepped the available modeswitch data for a Motorola product
id for a phone and came up empty. I started looking for apps for the
phone. I don't mind paying, I just didn't want to root the phone. Most
apps wanted to root the phone but I found easytether lite which worked
except that the light version won't do https, gmail and a few other

You have to install some client software on the computer. This app
seems to bypass modeswitching and this is the odd part, in order to
use the app you select "manage sim card" as the connection option. You
also have to allow debug access on the phone.

I would expect that this would mount the sim card as a block device
but when the app's usb function is enabled on the phone these devices
show up

crw-rw---T 1 root dialout 4, 64 Mar 24 20:07 ttyS0
crw-rw---T 1 root dialout 4, 65 Mar 24 20:07 ttyS1
crw-rw---T 1 root dialout 4, 66 Mar 24 20:07 ttyS2
crw-rw---T 1 root dialout 4, 67 Mar 24 20:07 ttyS3

as opposed to showing up as ttyUSBS0 etc. as they do when
usb_modeswitch does the work.

In any case and however it is done, I'm assuming hooks into the
Android Debug Bridge, it worked well enough that I registered my copy
and can access all features.

On 3/18/14, Russell <rreiter91-Re5JQEeQqe8AvxtiuMwx3w at> wrote:
> 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
> MessageContent="55534243123456780000000000000601000000000000000000000000000000"
> 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.
> Thanks
> Russell
> 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?
> --
> Sent from my Android phone with K-9 Mail.
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