-$Id: options.texi,v 1.1 1994/03/30 20:36:34 wollman Exp $
+$Id: options.doc,v 1.8 1994/06/08 23:42:02 phk Exp $
This file documents the configuration options available in the
FreeBSD operating system.
This option will likely be replaced by run-time configuration in a
future release of FreeBSD.
+`options "DISKLABEL_UNPROTECTED"'
+ This options disables the checks which normally protects the
+ disklabel from being overwritten. This allows dd of=/dev/rwd0d
+ if=file bs=8k to restore an diskimage.
+
`pseudo-device ether'
This pseudo-device provides link-layer support for Ethernet device
drivers. It is mandatory for all systems which include Ethernet or
temporary-space-intensive operations such as compilations. See the
`mount_mfs' manual page for more details.
+`options MULTICAST'
+ Enable multicast support for things like vat, nv, etc.
+
+`options MROUTING'
+ Enable multicast routing support (generally goes hand-in-hand with
+ the above). See also mrouted(1).
+
`options NFS'
The `NFS' option enables support for Sun's Network File System.
(Also called "Nightmare" or "Not a"....) This presently includes
will be replaced by run-time configuration in a future release of
FreeBSD.
+`options DUMMY_NOPS'
+ This option controls the use of real Nops for bus operations.
+ This might break on older systems so should be used with care.
+
Device Options
**************
glue logic, including DMA and autoconfiguration.
`controller aha0 at isa? port "IO_AHA0" bio irq 11 drq 5 vector ahaintr'
+`options "TUNE_1542"'
The `aha' device supports the Adaptec 154x series of SCSI
controllers, and attempts to support other vendors' controllers
which claim compatibility with the Adaptec 1542, such as the
distribution kernel. The `scbus' device (*note SCSI::.) is a
prerequisite for this device.
+ Some older versions of this code would attempt to set the
+ controller's bus access speed to the fastest possible without
+ losing data; we have found that this makes the driver unusable for
+ some users. If you wish to enable this optimization, or if you
+ suspect that your SCSI transfers are running slower than they
+ should, then you can use the `TUNE_1542' option to enable
+ bus-timing detection.
+
`controller bt0 at isa? port "IO_BT0" bio irq 12 vector btintr'
This device supports the Bustek 742 SCSI controller. It is
included in the `GENERICBT' distribution kernel; the `scbus' device
(*note SCSI::.) is a prerequisite.
-`options COM_BIDIR'
- This option enables bi-directional support in the `sio' serial
- driver. This option is slated for removal, at which time
- bi-directional support will always be enabled. See the
- `comcontrol' manual page for more information.
+`options ALLOW_CONFLICT_IOADDR'
+ Allow devices on the ISA bus to share conflicting IO address
+ spaces. This is generally an error, though things like PS/2 mouse
+ drivers which are implemented seperately from the keyboard driver
+ will require this option to be set. Note that this is almost
+ always sub-optimal, and the current PS/2 mouse driver will, in
+ fact, frequently fight with the keyboard if you try to use them
+ concurrently. Needing this option enabled is a sure sign that you
+ need to consider a different design for your driver.
+
+`options ALLOW_CONFLICT_IRQ'
+ Allow devices on the ISA bus to share conflicting IRQ's. This is
+ often necessary for multiport serial cards which have several
+ devices at the same IRQ. Enable this only with caution!
`options COM_MULTIPORT'
This option enables support in the `sio' serial driver for certain
The `is' network interface driver supports the Isolan 4141-0 and
Isolink 4110 Ethernet controllers.
-`device lpa0 at isa? port "IO_LPT1" tty'
+`device lpt0 at isa? port "IO_LPT1" tty'
`device lpt0 at isa? port "IO_LPT1" tty irq 7 vector lptintr'
- The `lpa' device provides support for the parallel printer driver
- accessed as `/dev/lp'. The `lpt' driver provides the same
- functionality, but only works with those printer controllers which
- support interrupt-driven operations. If you receive `ISA strayintr
- 7' messages correlated with the use of the `lpa' driver, chances
- are that your controller supports interrupt-driven operation, and
- you should switch to the `lpt' driver.
-
- The `lpa' driver is obsolete, and will be removed in release 1.2,
- to be replaced by special flags to the `lpt' driver.
+`device lpt0 at isa? port ? tty irq 7 vector lptintr'
+`device lpt0 at isa? port ? tty'
+ The `lpt' driver provides support for the parallel printer driver
+ accessed as `/dev/lptN' (N=0, 1, ...). The current version of
+ this driver provides support for either polled or interrupt-driven
+ ports, a unification of the `lpt' and `lpa' drivers from FreeBSD
+ 1.1.
+
+ The first and second examples show explicit selection of a port
+ address. If the port is not specified, as in the third and fourth
+ examples, the driver defaults to whatever address the BIOS printer
+ driver would have used. The second and third examples select
+ interrupt-driven I/O; if polled mode is specified, as in the first
+ and fourth examples, it is impossible to enable interrupt-driven
+ access at run time.
+
+ If you receive "ISA strayintr 7" messages correlated with the use
+ of the polled mode of `lpt', chances are that your controller
+ supports interrupt-driven operation, and you should switch to that
+ mode.
`device mcd0 at isa? port 0x300 bio irq 10 vector mcdintr'
This device provides support for the Mitsumi non-SCSI CD-ROM drive.
This driver supports Archive QIC-02 and Wangtek QIC-02 and QIC-36
cartridge tape controllers.
+`device ze0 at isa? port 0x300 net irq 5 iomem 0xd8000 vector zeintr'
+ This driver supports certain PCMCIA ethernet cards. It was originally
+ written for the IBM Credit Card Adapter and has also been tested
+ with the National Semi `InfoMover' PCMCIA card.
+
EISA-bus Devices and Options
============================