I/O operations
The following entry points are used
in non-STREAMS DDI 8 drivers
for the actual I/O operations:
biostart(D2)-
Handle all standard I/O operations
(reads and writes).
ioctl(D2)-
Handle custom I/O operations
requested by a user level process.
drvctl(D2)-
Handle custom I/O operations
requested by another driver.
This is similar to the
ioctl(D2)
entry point routine,
but handles requests coming from kernel level
rather than user level.
STREAMS drivers,
including MDI drivers,
use the following entry point routines
for I/O operations:
put(D2str)-
Receive messages from the preceeding queue.
The write put routine is required
for STREAMS drivers and modules,
but the read put routine is required
only for STREAMS modules;
STREAMS drivers do this processing in their
intr(D2str)
routine.
srv(D2str)-
Service queued messages.
This routine is optional for both
STREAMS drivers and modules
and is not used in MDI drivers
because the interface itself handles this processing.
Non-STREAMS drivers
for DDI versions prior to version 8
and ODDI drivers for SCO OpenServer 5
use the
read(D2),
write(D2),
and
strategy(D2)
(or
read(D2oddi),
write(D2oddi),
and
strategy(D2oddi))
entry point routines rather than
biostart(D2).
The actual I/O operations
are coded according to the I/O strategy
that the hardware supports. See
© 2005 The SCO Group, Inc. All rights reserved.
OpenServer 6 and UnixWare (SVR5) HDK - June 2005