intro.D4(D4)

NAME
     intro.D4 - introduction to kernel data structures

SYNOPSIS
     #include <sys/types.h>
     #include <sys/ddi.h>

DESCRIPTION
     This section describes the kernel data structures a developer might need
     to use in a device driver.

USAGE
     Driver developers should not declare arrays of these structures, as the
     size of any structure might change between releases.  Two exceptions to
     this are the iovec(D4) and uio(D4) structures.

     Drivers can only reference those structure members described on the
     manual page.  The actual data structures may have additional structure
     members beyond those described, but drivers must not reference them.

     Some structure members are flags fields that consist of a bitmask of
     flags.  Drivers must never directly assign values to these structure
     members.  Drivers should only set and clear flags they are interested in,
     since the actual implementation may contain unlisted flags.

     Data structures that are ``black boxes'' to drivers are not described in
     this section.  These structures are referenced on the manual pages where
     they are used.  Drivers should not be written to use any of their
     structure members.  Their only valid use is passing pointers to the
     structures to the particular kernel routines.