The Intelligent Input/Output (I2O) architecture allows hardware
drivers to be split into two parts: an operating system specific
module called the OSM and an hardware specific module called the
HDM. The OSM can talk to a whole range of HDM's, and ideally the
HDM's are not OS dependent. This allows for the same HDM driver to
be used under different operating systems if the relevant OSM is in
place. In order for this to work, you need to have an I2O interface
adapter card in your computer. This card contains a special I/O
processor (IOP), thus allowing high speeds since the CPU does not
have to deal with I/O.

If you say Y here, you will get a choice of interface adapter
drivers and OSM's with the following questions.

To compile this support as a module, choose M here: the
modules will be called i2o_core.

If unsure, say N.

source code:

drivers/message/i2o/