From MorphOS Library
AddUSBHardware - Manually add or remove USB hardware to/from MorphOS
DEVICE, UNIT/N, QUIET/S, REMOVE/S, ALL/S
DEVICE - required argument containing the (absolute) path and name of the USB hardware device driver to add or remove. UNIT - optional unit number, if multiple units are supported. Default is unit 0. QUIET - if used, no messages are printed into the shell. REMOVE - try to remove the entry, if found, instead of adding it. Be careful to use the same path/filename you used to add the hardware. ALL - tries to add all units of the given device. If REMOVE is specified, it removes all entries, effectively taking the stack offline.
Note: After adding the hardware driver, a class scan is done automatically.