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USB_MODESWITCH(1) General Commands Manual USB_MODESWITCH(1)


usb_modeswitch - control the mode of 'multi-state' USB devices


usb_modeswitch [-heWQDIvpVPmM23rwKdHSOBGTNALnsRiuagft] [-c filename]


Several new USB devices have their proprietary Windows drivers onboard, most of them WWAN and WLAN dongles. When plugged in for the first time, they act like a flash storage and start installing the Windows driver from there. If the driver is installed, it makes the storage device disappear and a new device, mainly composite (e.g. with modem ports), shows up.

On Linux, in most cases the drivers are available as kernel modules, such as "usbserial" or "option". However, the device initially binds to "usb-storage" by default. usb_modeswitch can then send a provided bulk message (most likely a mass storage command) to the device; this message has to be determined by analyzing the actions of the Windows driver.

In some cases, USB control commands are used for switching. These cases are handled by custom functions, and no bulk message needs to be provided.

Usually, the program is distributed with a set of configurations for many known devices, which allows a fully automatic handling of a device upon insertion, made possible by combining usb_modeswitch with the wrapper script usb_modeswitch_dispatcher which is launched by the udev daemon. This requires a Linux-flavoured system though.

Note that usb_modeswitch itself has no specific Linux dependencies.


This program follows the usual GNU command line syntax, with long options starting with two dashes ('--'). A summary of options is included below.

Show summary of options.
Print version information and exit
Vendor ID to look for (mandatory), usually given as hex number (example: 0x12d1). Each USB device is identified by a number officialy assigned to the vendor by the USB association and a number for the respective model (product ID) chosen by the vendor
Product ID to look for (mandatory)
Target vendor ID. When given will be searched for and detected initially for information purposes. If success checking (option -s) is active, providing target IDs (vendor/product) or target class is recommended
Return configuration number with MBIM interface and exit.
Target product ID
If bus and device number are provided, the handling of a specific device on a specific USB port is guaranteed, in contrast to using only the USB ID. This is important if there are multiple similar devices on a system
Target Device Class according to the USB specification. Some devices keep their original vendor/product ID after successful switching. To prevent them from being treated again, the device class can be checked. For unswitched devices it is always 8 (storage class), for switched modems it is often 0xff (vendor specific). In composite modes, the class of the first interface is watched
A specific endpoint to use for data transfers. Only for testing purposes; usually endpoints are determined from the device attributes
A bulk message to send as a switching command. Provided as a hexadecimal string
-2 --message-content2 STRING
-3 --message-content3 STRING
Additional bulk messages to send as switching commands. Provided as hexadecimal strings. When used with mass storage commands, setting --need-response is strongly advised to comply with specifications and to avoid likely errors
After issuing all bulk messages, wait for the given time before releasing the interface. Required for some modems on older systems (especially after an EJECT message)
Obsolete. CSW is always attempted to being read after mass storage transfers. No downside
Try to read the response to a storage command from there. Only for testing purposes; usually endpoints are determined from the device attributes
Apply the standard SCSI sequence of "Allow Medium Removal" and "Eject". Implies -n. One 'Message' can be added with -M that will be transmitted after the eject sequence. Used by many modems
Just detach the current driver. This is sufficient for some early devices to switch successfully. Otherwise this feature can be used as a 'scalpel' for special cases, like separating the driver from individual interfaces
Send a special control message used by older Huawei devices
Send a specific bulk message used by all newer Huawei devices
Send an alternative bulk message to Huawei devices
Send a special control message used by Sierra devices
Send a special control message used by GCT chipsets
Send a special control message used by Kobil devices
Send a special control message used by Sequans chipset
Send a special control message used by the MobileAction device
Send a special control message used by Qisda devices
Send a special control message used by Quanta devices
Send a special control message used by Pantech devices. Value NUM will be used in control message as 'wValue'
Send a special control message used by some newer Blackberry devices
Send a special control message used by all Option devices
Apply a special sequence used by Sony Ericsson devices. Implies option --check-success
Send a sequence of bulk messages used by Cisco devices
Send a USB reset command to the device. Can be combined with any switching method or stand alone. It is always done as the last step of all device interactions. Few devices need it to complete the switching; apart from that it may be useful during testing
Use a specific config file. If any ID or switching options are given as command line parameters, this option is ignored. In that case all mandatory parameters have to be provided on the command line
Provide device details in config file syntax as a multiline string on the command line
Read the device details in config file syntax from standard input, e.g. redirected from a command pipe (multiline text)
Don't show progress or error messages
Print all settings before running and show libusb debug messages
Changes the behaviour of the program slightly. A success message including the effective target device ID is put out and a syslog notice is issued. Mainly for integration with a wrapper script
After switching, keep checking for the result up to the given time. If target IDs or target class were provided, their appearance indicates certain success. Otherwise the disconnection of the original device is rated as likely proof
Obsolete. Formerly obtained SCSI attributes, now ignored
Select initial USB interface (default: 0). Only for testing purposes
Select USB configuration (applied after any other possible switching actions)
Select alternative USB interface setting (applied after switching). Mainly for testing


This manual page was originally written by Didier Raboud ( for the Debian system. Additions made by Josua Dietze. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU General Public License, Version 2 or any later version published by the Free Software Foundation.

The complete text of the current GNU General Public License can be found in