SC(4) BSD Kernel Interfaces Manual SC(4)
NAME
sc -- Sun Sun-2 SCSI bus host adaptor driver
SYNOPSIS
sun2
sc0 at mbmem0 addr 0x80000 ipl 2
sc1 at mbmem0 addr 0x84000 ipl 2
sun2 and sun4
sc0 at vme0 addr 0x200000 irq 2 vec 0x40
DESCRIPTION
The sc driver provides support for the Sun Microsystems "Sun-2" SCSI Bus Controller chipset found on various VME boards (Sun part #s
501-1045, 501-1138, 501-1149, and 501-1167) and on the "Sun-2 SCSI/Serial" (Sun part # 501-1006) Multibus board.
All versions of this driver can be configured with a flags directive in the config(1) file. The values are bits in a bitfield, and are
interpreted as follows:
0x0ff Set bit (1<<target) to disable SCSI parity checking
0x100 Set this bit to disable DMA interrupts (poll)
0x200 Set this bit to disable DMA entirely (use PIO)
For example: "flags 0x1ff" would disable DMA interrupts, and disable parity checking for targets 0-7. The "target" is the SCSI ID number of
a particular device on a particular SCSI bus.
SEE ALSO
cd(4), ch(4), intro(4), scsi(4), sd(4), st(4)
AUTHORS
Matt Fredette <fredette@NetBSD.org>,
David Jones,
Gordon Ross <gwr@NetBSD.org>,
Adam Glass <glass@NetBSD.org>,
Jason R. Thorpe <thorpej@NetBSD.org>.
BUGS
This SCSI chipset is rumored to have bugs in its handling of SCSI parity, therefore it is recommended that you disable parity on all SCSI
devices connected to this controller, and configure it with a 0x0ff value for its flags directive in the config(1) file.
This chipset has no support for raising the ATN signal, so there is no way to ever schedule a MSG_OUT phase on the bus. Currently, the
driver will ultimately reset the bus if this phase is ever requested by the upper layer SCSI driver.
This chipset has no support for SCSI disconnect/reselect. This means that slow devices, such as tape drives, can hog, or "lock up" the SCSI
bus.
This driver has not been tested in combination with non-SCSI devices behind Emulex or Adaptec bridges, which are common in Sun 2s and in Sun
Shoebox-type configurations. These devices pre-date the SCSI-I spec, and might not behave the way the chipset code currently expects.
BSD
June 28, 2001 BSD
Check Out this Related Man Page
SCSI(4) Kernel Interfaces Manual SCSI(4)
Name
SCSI - Small Computer System Interconnect
Description
The ULTRIX system interfaces to disk and tape devices through the Small Computer System Interconnect (SCSI). Initial ULTRIX SCSI support
is limited to the Digital-supplied mass storage devices. The following devices are fully supported on the ULTRIX system:
o Winchester disks: RZ22, RZ23, RZ23L, RZ24, RZ55, RZ56, RZ57, RX23, RX26, RX33
o Magnetic tapes: TZ30, TZK50, TLZ04, TSZ05, TKZ08, TZK10
o Optical disks: RRD40, RRD42
Under the ULTRIX operating system, a SCSI device is referred to by its logical name. Logical names take the following form:
nn#
The nn argument is the two-character name; the number sign (#) represents the unit number. The two character names for SCSI devices are:
rz - RZ22, RZ23, RZ23L, RZ24, RZ55, RZ56, RZ57, RX23, RX26, RX33, RRD40, RRD42 disks
tz - TZ30, TZK50, TLZ04, TSZ05, TKZ08, and TZK10 tapes
The unit number is a combination of the SCSI bus number, either 0, 1, ... and the device's target ID number. The unit number is eight
times the bus number plus the target ID. For example, an RZ23 disk at target ID 3 on bus 0 would be referred to as rz3; a TZK50 tape at
target ID 5 on the second SCSI bus would be referred to as 13.
The SCSI bus has eight possible target device IDs. By default, one is allocated to the system. This allows for a maximum of seven target
devices connected to a SCSI bus.
Restrictions
The ULTRIX SCSI device driver does not operate with optical disks, other than the Digital-supplied devices.
The SCSI driver attempts to support on a best effort basis, non-Digital-supplied winchester disks and magnetic tapes.
The following notes apply to the driver's handling of non-Digital-supplied disks:
o These disks are assigned a device type of RZxx, instead of RZ22, RZ23, RZ23L, RZ55, RZ56, RZ57, RX23, RX26, or RX33. The RZxx disks
follow the same logical device naming scheme as the Digital-supplied disks.
o During the autoconfigure phase of the system startup, the driver prints the contents of the SCSI vendor ID, product ID, and the
revision level fields of the inquiry data return by the SCSI device.
o RZxx disks are assigned a default partition table. The default table can be modified by editing the sz_rzxx_sizes[8] entry in the
file The utility can also be used to modify the partition table on a RZxx disk.
o The only logical unit number (LUN) supported for each target ID is 0.
See Also
rz(4), tz(4), chpt(8)
SCSI(4)