Intel Introduces USB4STREAM: Direct File Sharing Over USB4 in Linux Kernel 7.2
Intel is set to enhance file sharing capabilities in Linux with the introduction of a new driver, developed by Intel maintainer Mika Westerberg, which will be merged into Linux kernel version 7.2. Scheduled for release in June 2026, this driver brings the innovative USB4STREAM protocol to the Linux ecosystem, enabling users to transfer files directly over USB4 connections without relying on traditional network drivers.
Seamless File Transfers Without Network Dependencies
The USB4STREAM protocol is designed to simplify the process of backing up, transferring, and accessing files between two or more systems connected via USB4 or Thunderbolt cables. Unlike conventional methods that require network configuration, USB4STREAM operates independently of the network stack, allowing for direct data transfer through a dedicated character device interface.
This new approach not only streamlines file sharing but also opens up possibilities for sharing hardware resources, such as webcams or input peripherals, across connected devices. By bypassing the network layer, users can expect lower latency and improved security for local transfers.
Technical Implementation and Setup
Currently, setting up USB4STREAM requires some manual configuration using the ConfigFS interface. The developer has provided detailed examples and command-line instructions to help users get started. Once configured, the protocol enables data streams to be controlled by the receiving device, offering flexibility and control over the transfer process.
The character device created by the driver appears as /dev/tbstreamX, where X represents the minor device number starting from 0. Any application capable of utilizing standard read(2) and write(2) system calls can interact with the device, making integration straightforward for developers and users alike.
Potential for App Development and Hardware Sharing
With USB4STREAM, developers have the opportunity to build applications that offer seamless local file transfers, similar to popular tools like LocalSend, but without the need for a network connection. The protocol’s design also supports the sharing of hardware peripherals, further expanding its utility in multi-device environments.
As USB4 and Thunderbolt interfaces become increasingly common in modern hardware, the introduction of USB4STREAM in Linux kernel 7.2 marks a significant step forward in direct device-to-device communication, enhancing both convenience and performance for Linux users.
