USB is short for Universial Serial BUS. There are currently five variants of USB. The new USB stack in FreeBSD -current supports Low, Full and High speed USB devices in Host- and Device Mode.

• Low Speed USB
• Full Speed USB
• High Speed USB
• Super Speed USB (not supported yet)
• Wireless USB (not supported yet)

This page describes HPSUSB/'USB2' which is available in FreeBSD 8-CURRENT. The USBTODO page lists any known items that need fixing.

• Q: hald is using 100% CPU
• Q: xsane does not detect my scanner
• Q: Do I need to recompile the software before it can use libusb20 instead of libusb-0.1.x?
• Q: How do I re-link an application to use libusb20?
• A: Update to the latest 8-CURRENT and ports tree, libusb has been fully integrated

• Q: I see the following error and USB stops working “Page offset was not preserved!”
• A: Update your sources, this issue is fixed.

• Q: I can't boot my Freesbie using USB2.
• A: Update your sources, this issue is fixed.

• Q: My mass storage device is not working, what can I do?
• A: If your mass storage device needs a quirk, because it does not conform to the SCSI specification you can add it in the following way:

# 1) Unload "usb2_storage_mass" if it is loaded.
# 2) Plug your device.
# 3) You might have to add a new entry for your device in /sys/dev/usb/usbdevs .
# 4) To get the VID+PID for your device you run "usbconfig -u X -a Y dump_device_desc"
# where X and Y are the numbers reported by ugen.
# For example:
usbconfig -u 4 -a 7 dump_device_desc

# 5) Try adding an entry in the quirktable in /sys/dev/usb2/storage/umass2.c. 
# Look at the other quirks for examples.