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.
上面是linux i2o的選項，自己做的項目中的內核就有該模塊，終於知道爲啥要加它了。