`Fsys.amdscsi`

Driver for AMD 53c974/79C974 PCI SCSI Host adapters

Syntax:

Fsys.amdscsi [general_options...] [fsys fsys_options...]
             [amdscsi amdscsi_options...]...

Options:

general_options

If specified, the general_options must precede any fsys or amdscsi options:

-a unit=type

Add this unit to the driver's device list. You should find this option handy in situations where a SCSI device might not be powered up when the driver performs its scan. Without -a, the only devices the driver will support are those that respond during the scan. You can specify multiple -a options.

The unit can be one of the following combinations (the number of commas affects how the unit information is interpreted; see also the Examples section):

Specify	Meaning
controller`,`target`,`lun	fully specified controller, target, and LUN
controller`,`target	equivalent to controller`,`target`,0`
target	equivalent to `0,`target`,0`

In the type argument, you can specify one of the following SCSI device types:

type	String equivalent
`0`	`direct-access` (e.g. hard disk)
`1`	`sequential-access` (e.g. tape)
`2`	`printer`
`3`	`processor`
`4`	`WORM`
`5`	`CD-ROM`
`6`	`scanner`
`7`	`optical`
`8`	`medium_changer`
`9`	`communications`

To specify the type, you can use either the number or its string equivalent. When specifying a string, you need include only as many characters as are necessary to uniquely identify the type. For example to indicate type 1, you could specify se. Note that strings are case insensitive.

Not all of the above types are currently supported by the Filesystem Manager. See the -n option.

-L

Disable automatic scan for LUNs.

-q

Be quiet: don't display any information on startup.

-S scanmask

Target scan bitmask (default: 0xffff).

-v

Be verbose: display full information about SCSI units (devices) on startup.

fsys_options

The fsys_options control the driver's interface to Fsys. If specified, they must follow the fsys keyword:

-B num

Use this many 512-byte buffers for blocking/deblocking (default is 8). You need to specify this option if you have one or more units that don't use 512-byte sectors. CD-ROM units, for example, may use 2048-byte sectors.

The value of num is the sum of all the buffers required for SCSI units that use sectors larger than 512 bytes. To obtain the buffer required for a unit, you must use the following formula:

buf = (2*(sector_size / 512))

The value that should be used for num will be the sum of the results from all units.

-d

Allow concurrent I/O with other DMA-based drivers.

Some ISA motherboards have problems when on-board DMA and bus-mastering DMA occur concurrently. To avoid those problems, Fsys drivers which use DMA perform I/O concurrently only if the -d option is specified to either or both drivers. In general, you shouldn't use -d on an ISA machine if the floppy is going to be used at the same time as the SCSI hard disk. This option may be used safely on MCA and EISA machines.

-h head[,sect]

Report this many heads (and optionally sectors) to Fsys for hard disks (default is 64 heads, 32 sectors per track). The QNX filesystem doesn't need this information for normal operation. The information is needed only to let fdisk write the correct boot cylinder for booting.

-i

Ignore partition table when determining heads/sectors.

-l

("el") Disable locking while open on removable and tape devices.

-m num

Transfer no more than this many 512-byte sectors from the SCSI controller to memory in one operation (default is 127).

-M num

Allow no more than this many units to register with Fsys (default is the number of SCSI units available).

-n type=name

For the given SCSI unit type, use the specified name. For example, to have hard drives use /dev/scsin, you would specify -n 0=scsi. You can specify multiple -n options.

By default, the driver assigns names as follows:

type	String equivalent	Default name
`0`	`direct-access` (e.g. hard disk)	`hd`
`1`	`sequential-access` (e.g. tape)	`tp`
`4`	`WORM`	`wo`
`5`	`CD-ROM`	`cd`
`7`	`optical`	`mo`

As in the -a general option, you can specify the type using either the number or its string equivalent.

To have the driver ignore a type of device, specify an empty setting. For example, to ignore hard disks, specify -n 0.

-N name

Assign this unique version name to this invocation of the driver. The name can range from 1 to 8 characters in length.

-r

Reassign bad blocks automatically. If a bad block is found on a drive, a "REASSIGN BLOCKS" command will be given to the controller, causing the drive to map the block through a defect-mapping table.

Use this option with care since bad blocks could be erroneously reported by the device if the SCSI bus isn't properly terminated. If this occurs and you've specified -r, the defect-mapping table will be filled unnecessarily.

-R

Disable reserving the SCSI unit when the unit is open.

-s mins

Minutes of inactivity before stopping direct drive (default 0 == disabled)

-S

Try to always use scatter/gather.

amdscsi_options

The amdscsi_options control the driver's interface to the AMD 53c974 series controllers. If you've installed multiple controllers, you can repeat these options for each controller. Remember, however, to specify the amdscsi keyword before each controller's set of options.

-d: Disable disconnect.
-f: Enable Fast SCSI.
-p pci_index: The PCI index of the controller in the machine, where pci_index is a value between 0 and the number of adapters.
-r: Do not reset controller at initialization time.
-s SCSI_ID: The SCSI_ID used by the controller (7).
-S: Disable synchronous transfers.
-u num: Maximum number of SCSI units.

Description:

Fsys.amdscsi is the driver for AMD 53c974 and AMD 79c974 SCSI disk controllers.

For each controller, the driver performs a scan, looking for installed units. All targets are scanned (0 to 7) and for each target, each LUN (Logical Unit Number) is scanned (0 to 7). Devices are numbered starting from 0, and each type of device is numbered separately. For example, if you have a hard disk and a CD-ROM device, they'll be numbered hd0 and cd0, respectively.

Fsys.amdscsi will autodetect all AMD 53c974 and AMD 79c974 adapters by default, therefore you must specify the -p pci_index option to the driver if you want a specific SCSI adapter to be used.

The Filesystem Manager supports only the following types of SCSI units:

0: direct-access (e.g. hard disk)
1: sequential-access (e.g. tape)
4: WORM (write once/read multiple)
5: CD-ROM
7: optical

Tape units

If a tape unit is found during the driver's scan or if you specify a sequential-access unit with the -a general option, two block special files are created under /dev. By default, they're named /dev/tp0 and /dev/tpr0. Both these files reference the same physical drive, but /dev/tpr0 will perform a rewind on a close.

Examples:

Support an AMD 53c974 controller, list all connected devices:

    Fsys.amdscsi &

Support an AMD 53c974 controller with a pci_index of 1, list all connected devices:

    Fsys.amdscsi amdscsi -p1 &

Support an AMD 53c974 controller, list all connected devices, and register direct access devices as /dev/hardn and sequential access devices as /dev/tapen:

    Fsys.amdscsi fsys -n0=hard -n1=tape &

Files:

Fsys.amdscsi closes its standard input, standard output and standard error immediately after completing its initializations. Error messages may be produced during the initialization phase and will be written to standard error.

Fsys.amdscsi will cause Fsys to adopt various block special devices under /dev. These devices will normally be named hdn, where n is the physical unit number of the device. The base portion of this filename (hd) may be overridden by the -n option.

Exit status:

Fsys.amdscsi will terminate only if an error occurs during startup, or if it has successfully forked itself upon startup because it had not been initially started in the background.

0: Fsys.amdscsi was not started in the background and as a result forked itself. The original process terminated with a zero exit status, the forked process continued.
>0: An error occurred during startup.

Caveats:

Don't use slay to shut down a filesystem driver! If you do, new drivers may not be able to load properly and Fsys itself may experience internal errors.

If you need to shut down a filesystem driver, follow the steps in the "Driver shutdown" section in the documentation for Fsys.