Drivers that conform to earlier DDI versions can run on SVR5, but they cannot take advantage of the enhanced DDI features that are provided with SVR5 and will be harder to port to UDI, the next generation driver interface that will be used for future operating systems.
$ddi nonconformant drivers are generally much less portable than conformant drivers; such drivers that run on earlier releases of the SVR5 operating system may or may not run on SVR5.
See ``DDI interface versioning'' for background information about the DDI interface versioning scheme and ``UDI (Uniform Driver Interface)'' for more information about the UDI interface that is under development for future releases.
DDI 8 is significantly different from both DDI 7 and the SCO OpenServer 5 ODDI interfaces; a fair amount of rewriting is required when porting drivers.
Throughout the documentation DDI 8 is used to refer to all DDI 8 versions, including the multithreaded DDI 8mp version. In fact, most drivers should be multithreaded and so use DDI 8mp.
Whether porting a driver or creating a new driver, be sure to adhere to the guidelines in ``Guidelines for all kernel drivers'' and related sections.
This topic includes the following topics:
Additional information is provided in the following: