idata (instance data)

The term idata has two distinct meanings for SVR5 drivers:

DDI drivers

Beginning with DDI version 8, specific devices are identified by the idata and channel rather than by device number as in earlier releases. idata is returned by the CFG_ADD subfunction to the config(D2) entry point routine. See ``Device instance''.

SDI drivers

SDI HBA drivers use idata as shorthand to refer to the hba_idata_v5(D4sdi) structure and it's similarly named predecessors. This structure contains information that is specific to a given instance of a target (peripheral) device that is supported by the HBA driver.