Device Driver

This folder contains a minimal out-of-tree Linux kernel module that acts as a USB boot-protocol mouse driver.

It supports:

• Left and right buttons
• Scroll wheel
• Relative cursor motion (X/Y)

Important notes

• This is an educational example. Real USB mice are normally handled by the kernel HID stack (e.g. usbhid / hid-generic).
• This driver binds to HID Boot Mouse interfaces (class=HID, subclass=BOOT, protocol=MOUSE). Many mice work, but not all.
• To use it on a running system you typically must unbind the existing driver from that USB interface first.

Files

• usb_bootmouse.c – kernel module (USB driver + input device)
• Makefile – builds against your running kernel headers

Build

Install kernel headers/build deps (examples):

• Debian/Ubuntu: sudo apt-get install build-essential linux-headers-$(uname -r)
• Fedora: sudo dnf install @development-tools kernel-devel-$(uname -r)

Then build:

cd Device-Driver
make

Load

sudo insmod usb_bootmouse.ko
dmesg | tail -n 50

If you want to restrict binding to a specific device:

sudo insmod usb_bootmouse.ko match_vendor=0x046d match_product=0xc077

(Replace IDs with your mouse vendor/product from lsusb.)

Bind it to your mouse (unbind/bind)

1. Find the USB interface path.

You can use dmesg when plugging the mouse in, or inspect:

ls -l /sys/bus/usb/devices/

Typical interface names look like 1-2:1.0 (bus-port:config.interface).

2. Unbind the existing HID driver (commonly usbhid) from that interface:

DEVIF="1-2:1.0"   # <- change this
echo -n "$DEVIF" | sudo tee /sys/bus/usb/drivers/usbhid/unbind

3. Bind this module to the interface:

echo -n "$DEVIF" | sudo tee /sys/bus/usb/drivers/usb_bootmouse/bind

At this point, the driver should create an input device (via evdev).

Test

List input devices and find the new one:

cat /proc/bus/input/devices

Or use evtest:

sudo apt-get install evtest   # or your distro equivalent
sudo evtest

You should see events:

• BTN_LEFT, BTN_RIGHT
• REL_X, REL_Y
• REL_WHEEL

Unload

sudo rmmod usb_bootmouse

If you want the original HID driver back, bind it again:

echo -n "$DEVIF" | sudo tee /sys/bus/usb/drivers/usbhid/bind