Draisberghof | Software | USB_ModeSwitch | ModeSwitchForum

USB_ModeSwitch - Activating Switchable USB Devices on Linux

 
Version française içi - merci au Bullteam

If you don't like the text column width, adjust your browser window

Introduction

USB_ModeSwitch is (surprise!) a mode switching tool for controlling "flip flop" (multiple device) USB gear.

Several new USB devices (especially high-speed wireless WAN stuff, there seems to be a chipset from Qualcomm offering that feature) have their MS Windows drivers onboard; when plugged in for the first time they act like a flash storage and start installing the driver from there.
After that (and on every consecutive plugging) this driver switches the mode internally, the storage device vanishes (in most cases), and a new device (like a USB modem) shows up. The WWAN gear maker Option calls that feature "ZeroCD (TM)".

As you may have guessed, hardly anything of this is documented and Linux support by the better part of the makers is non-existent.
On the good side, most of the known devices do work in both modes with the available Linux drivers like "usb-storage" or "option" (an optimized serial driver for high-speed modems).
That leaves the problem of the mode switching from storage to modem or whatever the thing is supposed to do.

Fortunately there are things like human reason, USB sniffing programs and "libusb". It is possible to eavesdrop the communication of the MS Windows driver, to isolate the command or action that does the switching and to reproduce the same thing under the rule of Linux or the BSD variants.

USB_ModeSwitch makes the last step considerably easier by taking the important parameters from a configuration file and doing all the initialization and communication stuff.
From version 1.0.3 upwards there is a simple framework for integrating the switching with udev (the device manager) to make it fully automatic.

This tool is now on the way to be integrated into the big distributions; soon you should not be having to install from the source packages here anymore.
But I strongly advise against using packaged versions before 1.1.0.

 

Please read the information on this page carefully before you go around posting questions! If you encounter a new device, it really helps to understand the principle of what is happening, which in turn makes it easier to find out about the switching command and to add a new config entry.

For hints about doing your own sniffing see paragraph Contribute below.

Download

The latest release version is 1.1.4. The tar archive contains only the source. I used libusb-0.1.12 but the "compat" library from libusb-1.0 is now working smoothly too.

Important: you need the data package as well !!
Changes and updates to the configuration data may happen more often than new releases; most of the valuable knowledge about devices is contained in these files. That's why it is provided separately.

How to install

If you have an earlier version installed, de-installation is recommended ("make uninstall"). Several file locations changed in 1.1.0, old ones might be orphaned if not taken care of. If you have a version after 1.1.0 you can just update and overwrite all existing files.

Important: you need "tcl" for the wrapper script to work; if you enter "tclsh" and you get a "%" prompt, you are set (to exit enter "exit"). The "tcl" package is part of all distributions I know.

Unpack the source file of the program (who might have thought!). In the newly created directory run as root or superuser:

# make install
This installs a tiny shell script for udev, the larger wrapper script, a config file, the man page and the freshly compiled binary.
Now do the same for the data package. It will install the config files in /etc/usb_modeswitch.d and the udev rule file in /lib/udev/rules.d.
You are set already; if your device is known, you should be able to just plug it and use it. If it doesn't work right away we'll find out why.

For manual use just install the program. Work with the command line interface or with the original setup reference file. To do the latter you put "usb-modeswitch.setup" into "/etc" and edit it according to your hardware. It's heavily commented and should tell you what to do.
The setup file can have any name and place; just tell usb_modeswitch how to find it with the -c parameter.

Manual use is intended for testing and analyzing. See next paragraph.

How to use

In most cases, you should be able to use your device without any interaction except plugging your device in.

For testing, debugging and taming new devices from the wild, you can use the binary part of USB_ModeSwitch in manual mode.
There are two ways for that: using a config file or using the command line.

Run "usb-modeswitch -h" to list the command line parameters. If any of them except -W, -D, -I and -q are used, a config file given with -c is ignored and all mandatory parameters have to be provided on the command line. See also the included man page.

To work with a config file, use one of the little files in /etc/usb_modeswitch.d or create one yourself. Then give the path and file name to usb_modeswitch with the -c option. You also can have a look into the device_reference.txt (gzipped) for hints about model families and an explanation of the parameters.

Important: USB_ModeSwitch - like all programs using libusb - has to be run as root (or with "sudo") when calling it manually. Otherwise strange error messages turn up and things won't work. When trying out switching commands and strategies, it's probably easier to work at a root shell for a while ("sudo bash" or "su -").

The automatic approach consists of several components working together:

After switching and driver-loading, it is the responsibility of the system to discover the new (mostly serial) device.
When dealing with wireless devices, there may be issues with NetworkManager (or its ModemManager component) which does not seem to be overly reliable when trying to recognize a proper modem port.
Good results were reported by working with wvdial, UMTSmon and several tools providing a user interface to PPP like kppp; some of these programs may require a bit of basic knowledge though.

There is also a new - unusual but intriguing - concept which shortcuts the tedious path of putting together all components for a successful wireless broadband connection. The Sakis3G tool is a self-containing script (including among others the latest USB_ModeSwitch binary). It supports quite a number of providers already and is rapidly expanding. The beauty of it is that no installation is necessary and only a minimum of input required. Contrary to NetworkManager, it really delivers.
Check it out at Sakis' blog ToDo Forever. There is even a HowTo for setting it up so that it connects right away when a modem is plugged in.

The main hurdle for NetworkManager and others to a fully automated use of a newly switched modem is to find the right port for connecting. Often more than one serial port is created after switching (even up to five). Generally, not all of them are really standard serial (the driver can't decide), some may look like it and even accept AT commands, but usually the right one is providing an interrupt transfer endpoint. Unfortunately, NetworkManager does rely on other ways of probing for the correct port and sometimes fails. It is worth to note that the said Sakis3G tool is able to find this port quite easily.

Starting from version 1.1.2, usb_modeswitch will add a symbolic link to the correct port with interrupt transfer if the device provides standard serial ports. The link will have the name /dev/gsmmodem, with a number appended if more than one device is attached.
You can use this name with connection helpers like wvdial. Note that in many cases you may have to edit the configuration file manually.

If you managed to get a new or badly supported device to switch correctly in manual mode, you can add a udev rule and a config file yourself. But please report it back to share it !!

See Contribute.

Known working hardware

Very important note:
Personally, I could only test my Option Icon and the S.E. MD400; the list here - as well as all the necessary data - relies on reports from third parties (people, that is). So don't be surprised if you hit sudden obstacles even with your device listed here. You have been warned.

There are hitherto three known methods for initiating the switching process:

  1. sending a rarely used or seemingly weird standard storage command (equivalent to those of SCSI) to the storage device ("eject" for example)
  2. actively removing (rather detaching) the storage driver from the device
  3. sending a certain control message to the device

Again, if you don't find the name of your device in this list, it may still be supported. The important thing is that you find your device's USB ID in the config file folder. Have a look into the latest data package (See Download.).

Troubleshooting

Note: if you still need support after having followed the advice on this page, please use the forum! E-mail may be used for device/config contributions.

Known quirks:

For debugging of the automated system integration, edit (as root or su) /etc/usb_modeswitch.conf in a text editor and change the line 

 EnableLogging=0
to 
 EnableLogging=1
This gives you a verbose output of the hotplug activity to /var/log/usb_modeswitch_<device>.

If you're next to certain that you have the right values for your device, followed all the hints (see Known working hardware), and USB_ModeSwitch seems to do something run after run but to no effect, there are most likely system issues involved.

The first suspects are existing system rules for modems which handle things not quite correctly.
If you own a device with the unswitched ID of 05c6:1000, it will most likely get a wrong switching command. There are four different types of switching devices, all with that same ID; in the big distributions they are all treated alike as a model from "Option" (the manufacturer) which is wrong in three out of four cases. There are even cell phones with that ID which get the same treatment when connected to an USB port.

To fix problems like that you can try to remove rules files from "/lib/udev/rules.d" which contain calls to "modem-modeswitch".
USB_ModeSwitch will do additional checks beside the USB ID and treat all known ambiguous devices in the right way. Furthermore, it leaves unknown devices with the 05c6:1000 ID alone.

Annother notorious candidate is again 19d2:2000. It may be switched O.K. by an existing rule, but there is no driver loading if your model is new and its ID is not yet added to the "option" module.
Disable the rule running "eject" and the ID will be handled by usb_modeswitch.

Kernel related issues

In some newer kernels, certain device families (some Option, some Huawei, some ZTE as mentioned above) get a special treatment in the usb-storage code to enable switching right away. You would not need USB_ModeSwitch anymore for these specific dvices; on the other hand you have no choice of accessing the "CD-ROM" part of your device. Plus, there were cases when the special treatment brought no results and furthermore prevented USB_ModeSwitch to work properly afterwards (happened with ZTE devices, error "-2").

In case of trouble, look into "unusual_devs.h" in the "drivers/usb/storage" folder of your kernel source. If your default ID (vendor and product ID of the storage part) can be found there and you get errors when running USB_ModeSwitch, try first to blacklist "usb-storage".
If that helps, you should consider rebuilding your kernel with the entry in "unusual_devs.h" deactivated. The only thing that will happen is that usb-storage works in the default way afterwards.
I found a tip in the Russian Gentoo wiki to do exactly what I just suggested for the ZTE MF626.

Annother way of influencing the kernel behaviour is the parameter "delay_use" of "usb-storage" which sets the time in seconds after plugging when the storage device will actually be used (and probably automounted). The default value is 5; this might affect the switching result under certain conditions.
To change the default add in /etc/modprobe.conf: 

 options usb-storage delay_use=1 (or 10, or other)
I will try and monitor - possibly influence - further kernel development to prevent unpleasant surprises in the future.
Between the kernel USB developers there is a consensus about future removal of any switching code from the kernel if the "userspace" handling is broadly working and available.

Contribute

USB_ModeSwitch comes quite handy for experimenting with your own hardware if not supported yet. You could try this approach:

Note the device's Vendor and Product ID from /proc/bus/usb/devices (or from the output of "lsusb"); the assigned driver is usually "usb-storage". Then try spying out the USB communication to the device with the same ID inside M$ Windoze.
I recommend this tool: "SniffUSB" (http://www.pcausa.com/Utilities/UsbSnoop/default.htm).

This is the extremely short version. There is a very good case example from Mark A. Ziesemer here:
Alltel UM175AL USB EVDO under Ubuntu Hardy Heron

Please post any improvements, new device information and/or bug reports to the ModeSwitchForum !
If you don't need support you can also send me an old-fashioned - and at your demand confidential - e-mail (see below).

Whodunit

Copyright (C) 2007, 2008, 2009, 2010 Please use the forum for support questions! For other messages like tested new device configurations or personal/confidential stuff you can mail me directly.

Other contributors

Command line parsing, decent usage/config output and handling, bugfixes added by: TargetClass parameter implementation to support new Option devices/firmware: Created with initial help from: Config file parsing stuff borrowed from: Hexstr2bin function borrowed from: Code, ideas and other input from: More contributors (device specific) are listed in the device_reference.txt (gzipped). Thanks to everyone at the forum too! Sometimes it takes a considerable reservoir of patience until success ...

History

Version 1.1.4, 2010/08/17
The package should work at boot time now (cold and warm); product IDs of "0000" do exist but were not accepted, fixed (thanks to Sakis Dimopoulos); response endpoint is now always detected (led to possible error report when resetting all endpoints in version 1.1.3); wrapper script can now work with a packed collection of config files as well as with the plain folder of files; use with the "install-packed" make target of the data package (for use on systems with resource constraints); wrapper fix for the symlink feature: handling of multiple interrupt ports was incomplete; wrapper does not longer use a temporary file for the symlink feature (security considerations, Marco d'Itri)
Version 1.1.3, 2010/06/21
Added delay option to separate multiple message transfers by millisecs; fixed (possibly dangerous) sloppy string handling (thanks to Christophe Fergeau); added "clear_halt" for response endpoint; small additions in Makefile (install with -D); changes in option handling (no more default config file!) and help text; symlink feature in wrapper can now cope with devices providing more than one interrupt port; wrapper now ignores package manager leftovers in config folder; replaced bash-specific syntax in wrapper; changed ZTE skipping (if existing rules are found) to warning
Version 1.1.2, 2010/04/18
Attention: data package now separated from program package! Add support for two additional bulk messages (for Pirelli devices); wrapper handles special ZTE case; generalized driver loading, new parameter "DriverModule" and "DriverIDPath"; new wrapper facility to add symlink pointing to interrupt port (used in rule file from data pack >= 20100418)
Version 1.1.1, 2010/03/17
Attention: old usb_modeswitch.conf renamed to usb_modeswitch.setup! Add separate config file for wrapper (global settings for switching and logging); add config file option to disable driver loading; handling of kernel attribute AVOID_RESET_QUIRK added; bug fixed in SonyMode (reported by "no-0n3"); bug fixed in SuccessCheck logic; minor flow alignments and fixes; new devices
Version 1.1.0, 2010/01/24
Attention: wrapper script location changed, uninstall old versions! Major fixes in the wrapper script (stabilizing and time-saving); back to unified installation, defaults to "integrated" approach; new -D parameter to enable "integrated" behaviour; bugs fixed in success check; man file included (borrowed from the Debian package); C code and binary works with the compat library from libusb-1.0; some new devices
Version 1.0.7, 2010/01/06
Bug fixed for Sony mode, thanks to Marco Chiaranda; fix for parameter substitution in newer udev versions, fix for bad bug in wrapper script practically disabling automatic mode
Version 1.0.6, 2009/12/21
New "GCT Mode", fixes for device quirks (NXP Dragonfly), fix for multiple Huawei devices, cleanups, loads of new devices in config file and database, minor tcl script changes
Version 1.0.5, 2009/08/26
More changes and fixes regarding success check; "--version" option; config "database" updated
Version 1.0.4, 2009/08/23
    Success check bugs (and others) fixed
Version 1.0.3, 2009/08/20
Success check improved; experimental system integration (fully automated), optional; new parameter "TargetProductList" needed for this; other necessary small adaptations; more devices
Version 1.0.2, 2009/06/09
    Some output bugs fixed
Version 1.0.1, 2009/06/08
    Added output of descriptor strings for further identification
Version 1.0.0, 2009/06/03
Attention: possible incompatibilities for command line control! On/off flags don't require arguments anymore (-H, -S, -O, -d, -R, -n, new: -I), meaning "-R 0" does a reset like "-R 1" or "-R"; long option names changed to standard format (e.g. --HuaweiMode to --huawei-mode); added device inquiry, for future help with device identification; catch error -19 as possible success; send and response endpoints now autoselected (consequently NeedResponse is back); code cleanup; new devices
Version 0.9.7, 2009/04/15
    Updated SonyMode, MD 400 now stable; automatic default endpoint detection from Andrew Bird
Version 0.9.7beta, 2009/03/15
    Major code clean up, optional success control (both suggested by Daniel Cooper), new devices
Version 0.9.6, 2009/01/08
    Special modes added for Sierra and Sony Ericsson, new devices
Version 0.9.5, 2008/10/27
    New options for USB tuning added (jokedst), lots of new devices, clean up
Version 0.9.4, 2008/06/09
    Compat fix for libusb on FreeBSD quirks, more devices
Version 0.9.4beta2, 2008/03/19
    Udev 'release' fix
Version 0.9.4beta, 2008/03/16
    Multiple device support
Version 0.9.3, 2008/03/09
    More devices, no other changes from 0.9.3beta
Version 0.9.3beta, 2007/12/30
    New TargetClass parameter for recent Option firmware (Paul Hardwick), more devices
Version 0.9.2, 2007/11/02
    New Huawei mode (code from Miroslav Bobovsky, added by Denis Sutter), more devices
Version 0.9.1beta, 2007/09/11
    Added command line parsing (jokedst), cleaned up config stuff (jokedst), bug fixes, doc updates
Version 0.9beta, 2007/08/12
    Name change from "icon_switch", parameter file and generalizing
Version 0.2, 2006/09/25
    Code cleaning, more messages
Version 0.1, 2006/09/24
    Just very basic functionality ...

Legal

This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details:
http://www.gnu.org/licenses/gpl.txt

Page last revised: 2010-08-26