sc01(7)


sc01 -- CD-ROM Target Driver

Description

sc01 is a Storage Device Interface (SDI)-compliant CD-ROM target driver that provides access to one or more CD-ROM drives. Each drive must be attached to a SCSI bus controlled by an SDI-compliant host adapter driver (for example, see adsc(7)).

Access to a particular drive is accomplished using the sc01 device files located in /dev/[r]cdrom. Each device file identifies a particular drive based on the SCSI ID assigned to that drive. The binding between a device file and a CD-ROM drive is as follows:


/dev/rcdrom/cd0
CD-ROM drive with lowest SCSI ID

/dev/rcdrom/cd1
CD-ROM drive with next to lowest SCSI ID
and so on.

Most CD-ROM drives can handle CD-ROM disks that contain two types of data: informational data and audio data. The sc01 driver allows access to both types of data.

A CD-ROM disk that contains informational data is treated as a random-access storage device, such as a hard disk. The information on the disk is divided into consecutively numbered, fixed-size (usually 2KB) sectors that can be accessed in any order. The standard tools for reading data from a random-access device, such as dd(1M) or read(2), can be used to read informational data from a CD-ROM. However, all write operations are prohibited.

Audio commands control the operation of the drive's audio output hardware (usually a headphone jack located on the drive). For example, the C_PLAYAUDIO ioctl(2) causes the audio hardware to decode and convert the audio data to analog at a specific location on the disk, and play the audio on the drive's audio output hardware. Audio data is not returned to the host system.

All audio data commands are executed through the ioctl interface and often require a parameter structure that identifies the audio data to be acted upon. Unlike informational data, audio data is not referenced by a sector address. The methods used to identify a particular section of audio data should be described in the SCSI interface section of the reference manual supplied with your CD-ROM drive. Audio data cannot be read as if it were informational data, and informational data cannot be played using the drive's audio hardware.

sc01 device nodes


/dev/cdrom
Nodes in this directory provide ``Block I/O'' access to the represented CD-ROM drives.

cCbBtTlL

C
Controller Number

B
SCSI Bus Number

T
SCSI Target ID

L
SCSI Logical Unit Number

/dev/rcdrom
Nodes in this directory provide Raw (Character) I/O access to the represented CD-ROM drives.

cCbBtTlL

C
Controller Number

B
SCSI Bus Number

T
SCSI Target ID

L
SCSI Logical Unit Number

cdromN

N
Drive number. The drives are numbered sequentially, as they are found by the system, starting at 1.

ioctl calls

The sc01 driver uses several ioctl(2) commands. These are documented on the sdi(7) manual page.

Files


/usr/include/sys/cd_ioctl.h

/usr/include/sys/cdrom.h

/usr/include/sys/sc01.h

/etc/conf/pack.d/sc01/space.c

/dev/[r]cdrom/cd*

/usr/include/sys/scsi.h

/usr/include/sys/sdi.h

/usr/include/sys/sdi_edt.h

References

adsc(7), dpt(7), ioctl(2), mcis(7), sd01(7), sdi(7), st01(7), sw01(7), wd7000(7)
© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 25 April 2004