devhidraw0

/dev/hidraw0 is a character device node that represents the first raw Human Interface Device (HID) interface provided by the Linux kernel. It resides in the /dev directory and is part of the hidraw subsystem, which offers a low‑level, unprocessed communication channel to HID peripherals such as keyboards, mice, game controllers, and specialized input devices. Unlike higher‑level input drivers that interpret and translate HID reports into generic input events, the hidraw interface presents the raw report data exactly as it is transmitted over the USB or Bluetooth bus.

The device node is created automatically by the kernel when a compatible HID device is attached and the hidraw driver is loaded. Its major number is 10 and the minor number is typically 0 for the first device, incrementing for each additional raw HID interface (e.g., /dev/hidraw1, /dev/hidraw2). Access permissions are governed by udev rules; by default they are readable and writable only by root, though distributions may add rules to permit use by specific user groups such as “input”.

Software that requires direct access to HID reports—custom firmware loaders, device configuration utilities, or diagnostic tools—opens /dev/hidraw0 with standard file operations (open, read, write, ioctl). Data exchanged through the node consists of binary report packets defined by the device’s HID report descriptor. Because the interface bypasses kernel input processing, applications must handle report parsing, device-specific command structures, and error checking themselves.

The hidraw subsystem can be disabled at compile time or via kernel configuration options (CONFIG_HIDRAW). When disabled, the corresponding /dev/hidraw* nodes are not created, and only higher‑level input drivers remain available. Use of /dev/hidraw0 is generally reserved for advanced users and developers who need precise control over HID communication.