DDI and ODDI driver interfaces

DDI (Device Driver Interface) is the basic interface used to write kernel-level drivers for OpenServer 6 and UnixWare 7 systems. ODDI (OpenServer 5 Device Driver Interface) is the OpenServer 5 equivalent. These interfaces provide entry-point routines, kernel functions, and kernel structures for functionality such as data transfers, synchronization, and autoconfiguration of drivers.

DDI 8 and DDI 8mp are the most recent versions supported on OpenServer 6 and UnixWare 7; ODDI 5 and ODDI 5mp are the most recent versions supported on OpenServer 5. The DDI and ODDI interfaces also include the STREAMS interface, but STREAMS is documented separately. See the Product Documentation for the following references.

DDI is documented in the following:

  • Section D1 manual pages
  • Section D2 manual pages
  • Section D3 manual pages
  • Section D4 manual pages
  • Developing OpenServer 5 kernel drivers

ODDI is documented in the following:
  • Section D2oddi manual pages
  • Section D3oddi manual pages
  • Section D4oddi manual pages
  • Developing OpenServer kernel drivers

DDI and ODDI are different in many ways but also have similarities. See the individual manual pages for entry point routines, functions, and structures for information about equivalent functionality on the other platform. Some other useful documentation pointers include:
  • For information about implementing specific functionality on both platforms, see the HDK Technical Reference.
  • For information about porting drivers from OpenServer 5 to OpenServer 6 or UnixWare 7, see ``Porting drivers to DDI 8''.
  • For information about new features in DDI8 and OpenServer 6, see ``New driver features in DDI 8''.
  • For general guidelines about implementing kernel-level drivers on both platforms, see ``Guidelines for all kernel drivers''.