udev (userspace /dev) is a device manager for the Linux kernel. It can be used for the following:

  • Add actions to the attachment/removal of certain devices.

  • Make devices available without root privileges.

  • Recognize older devices

  • Load UVC extension units.

The udev rules file is generated during the build step; the template is located at data/udev/

The default installation path is: /etc/udev/rules.d

For more information, refer to the man pages of udev (7,8).

Applied rules

The following rules are applied to all USB devices:

Access rights

SUBSYSTEM=="usb", ATTRS{idVendor}=="199e", \
                  GROUP="video", MODE="0666", TAG+="uaccess", TAG+="udev-acl"

Extension Unit Loading

Most UVC devices from The Imaging Source offer uvc extension units. These are loaded automatically when the camera is connected to ensure full operability.

ACTION=="add", SUBSYSTEM=="video4linux", \
               ATTRS{idVendor}=="199e", ATTRS{idProduct}=="<DEVICE productID>", \
               RUN+="/install-path-to/tcam-uvc-extension-loader --device=/dev/%k -f /install-path-to-uvc-extension-unit/extension.json"

Depending on the device used different uvc extension units may be loaded. For further information, see UVC extension units.