What drivers should be BTLD
Drivers should be boot-time loadable
if they are not part of the standard
installation kernel but they are
required to install the operating system.
These include:
-
Any driver for a disk device
(SCSI or non-SCSI,
and including SCSI host adapters
as well as the SCSI peripheral driver),
so it can be used for the primary hard disk
on which the root filesystem is loaded.
-
Any driver for a tape or CD-ROM device
(SCSI or non-SCSI,
and including SCSI host adapters
as well as the SCSI peripheral driver)
that could be used as distribution media
for the operating system.
-
Any driver that will be included
in the SCO Advanced Hardware Supplement (AHS)
and is not a Network MDI,
Advanced Graphic Adapter,
or Multiprocessing platform (GPI) driver.
In SCO OpenServer 5 Release 5 onwards, a BTLD can be used
to replace an existing driver if the ahslink command
is used to load the driver rather than the
link(HW)
command.
In a future release, this functionality of ahslink
will be merged into link.
Note the following restrictions on BTLDs:
-
STREAMS drivers cannot be boot-time loadable.
-
Pseudo-drivers, STREAMS modules,
and other software drivers that are not accessed
through the cdevsw and/or bdevsw tables
cannot be boot-time loadable.
-
A replacement driver's Master file entry
must match the existing Master file entry exactly
or the BTLD driver will be installed
as a new driver rather than replacing the existing driver.
-
Some driver characteristics defined in the
mdevice(F)
file cannot be used for BTLDs.
See the ``Limitations'' section of the
btld(F)
manual page for a detailed list.
-
``Guidelines for writing BTLDs''
contains a list of restrictions for coding
a BTLD.
© 2005 The SCO Group, Inc. All rights reserved.