Technical data

xy(7D) Devices SunOS 5.5
NAME xy, xyc − disk driver for Xylogics 450 and 451 SMD Disk Controllers
SYNOPSIS xyc@2d,ee40/xy@slave,0:partition
xyc@2d,ee48/xy@slave,0:partition
AVAILABILITY SPARC
Only available on Sun-4/200, Sun-4/300, and Sun-4/400 series systems.
DESCRIPTION The driver for Xylogics 450/451 devices consists of several components: a controller
driver module (xyc) and a slave device driver module (xy). Each driver module has an
associated configuration file, which lives in the same directory as the driver module. See
driver.conf(4) and vme(4) for the interpretation of the contents of these files.
The block files access the disk using the system’s normal buffering mechanism and may
be read and written without regard to physical disk records. There is also a raw interface
that provides for direct transmission between the disk and the user’s read or write buffer.
A single read or write call usually results in only one I/O operation; therefore raw I/O is
considerably more efficient when many words are transmitted. The physical names of
the raw files conventionallyhave ‘,raw’ appended to them. The logical names for the raw
files live in the /dev/rdsk directory, as usual.
When using raw I/O, transfer counts should be multiples of 512 bytes (the size of a disk
sector). Likewise, when using lseek(2) to specify block offsets from which to perform
raw I/O, the logical offset should also be a multiple of 512 bytes.
Partition 0 is normally used for the root file system on a disk, partition 1 as a paging area
(for example, swap), and partition 2 for backing up the entire disk. Partition 2 normally
maps the entire disk and may also be used as the mount point for secondary disks in the
system. The rest of the disk is normally partition 6. For the primary disk, the user file
system is located here.
Due to word ordering differences between the disk controller and Sun computers, user
buffers that are used for raw I/O must not begin on odd byte boundaries.
DISK SUPPORT This driver handles allSMD drives by reading a label from sector 0 of the drive which
describes the disk geometry and partitioning.
FILES /kernel/drv/xyc driver module
/kernel/drv/xy driver module
/kernel/drv/xyc.conf driver configuration file
/kernel/drv/xy.conf driver configuration file
/dev/dsk/cXdYsZ block device, controller X, unit Y, slice Z
/dev/rdsk/cXdYsZ raw device, controller X, unit Y, slice Z
SEE ALSO lseek(2), read(2), write(2), driver.conf(4), vme(4), dkio(7I), hdio(7I)
7D-410 modified 20 Jul 1994