The cdt (CD tape) driver overlays Srom to provide a cartridge tape-like interface. Data on the CD-ROM can then be accessed using utilities normally used to access a cartridge or SCSI tape. This technology is used for reading older installation CDs.
The command mkdev cdrom is used to configure the CD-ROM driver interactively. This defines the SCSI host adapter, controller target ID, and device LUN in the SCSI configuration file mscsi(F).
The CD-ROM device driver does not print its configuration message until the first open of a CD-ROM drive after a reboot of the system.
The character special device files (/dev/rcd) support raw I/O in multiples of the physical sector size of the CD-ROM (typically 2KB).
The block special CD device files (/dev/cd) support buffered I/O and enable a CD-ROM to be mounted as an HS filesystem. See mount(ADM) for details of the features of High Sierra, Rock Ridge, and ISO 9660 CD-ROM formats that are supported.
The minor device number determines which compact disk unit will be accessed; minor number 0 accesses the first device, 1 the second device and so on, up to minor number 255.
NOTICE: Srom: Spurious interruptNo command was pending when an interrupt was received.
CONFIG: cdt: Block device name (--/minor) driver not installedThe major device number corresponding to the underlying physical device could not be calculated.
CONFIG: cdt: Device name unit m (cdt_unitnum) not CD-ROM tape unit nThe underlying physical device must be a CD-ROM drive.
WARNING: cdt: Unrecognized data format on dev device (major/minor)The data format on the disk was not recognized.