Added first tries

README.md

@@ -1,3 +1,116 @@
 
 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:
+
+```bash
+cd Device-Driver
+make
+```
+
+Load
+----
+
+```bash
+sudo insmod usb_bootmouse.ko
+dmesg | tail -n 50
+```
+
+If you want to restrict binding to a specific device:
+
+```bash
+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:
+
+```bash
+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:
+
+```bash
+DEVIF="1-2:1.0"   # <- change this
+echo -n "$DEVIF" | sudo tee /sys/bus/usb/drivers/usbhid/unbind
+```
+
+3) Bind this module to the interface:
+
+```bash
+echo -n "$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:
+
+```bash
+cat /proc/bus/input/devices
+```
+
+Or use `evtest`:
+
+```bash
+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
+------
+
+```bash
+sudo rmmod usb_bootmouse
+```
+
+If you want the original HID driver back, bind it again:
+
+```bash
+echo -n "$DEVIF" | sudo tee /sys/bus/usb/drivers/usbhid/bind
+```