How To Guide How to setup and configure a Universal Serial Bus (USB)

How to setup and configure a Universal Serial Bus (USB)

This guide assumes a generic knowledge of how USB works, and how it is used under Linux. Please read the first few sections of the Linux-USB guide at www.linux-usb.org before proceeding.

USB support provided with the 2.6 kernel is a little different from the 2.4 version. This page summarizes some of the differences.

When building the kernel, it is no longer necessary to have PCI support enabled to use USB. All STMicroelectronics' boards use an OHCI controller (USB 1.1). This can be enabled directly in the kernel configuration, together with any class drivers required.

When the root file system is accessed through a USB device it may be necessary to delay mounting the file system until the USB device has been recognized. This is done using the rootdelay=<sec> kernel command line option, where <sec> is the delay in seconds.

A similar problem exists when using the command line IP auto-configuration for USB-attached Ethernet devices. In this case, the kernel command line option ipconfdelay=<sec> can be used; again <sec> is the delay is in seconds.

USB standards information

• USB Implementer's Forum

• USB-IF Developer's page

• USB OpenHCI Specification

Linux-USB information & drivers

• Linux-USB website

• Linux-USB guide

• Linux-USB devices database