CD(9) BSD Kernel Developer's Manual CD(9)NAMEcd — CDROM driver for the CAM SCSI subsystem
DESCRIPTION
The cd device driver provides a read only interface for CDROM drives
(SCSI type 5) and WORM drives (SCSI type 4) that support CDROM type com‐
mands. Some drives don't behave as the driver expects. See the section
QUIRKS for info on possible flags.
QUIRKS
Each CD-ROM device can have different interpretations of the SCSI spec.
This can lead to drives requiring special handling in the driver. The
following is a list of quirks that the driver recognize.
CD_Q_NO_TOUCH This flag tell the driver not to probe the drive at
attach time to see if there is a disk in the drive and
find out what size it is. This flag is currently unim‐
plemented in the CAM cd driver.
CD_Q_BCD_TRACKS This flag is for broken drives that return the track
numbers in packed BCD instead of straight decimal. If
the drive seems to skip tracks (tracks 10-15 are
skipped) then you have a drive that is in need of this
flag.
CD_Q_NO_CHANGER This flag tells the driver that the device in question
is not a changer. This is only necessary for a CDROM
device with multiple luns that are not a part of a
changer.
CD_Q_CHANGER This flag tells the driver that the given device is a
multi-lun changer. In general, the driver will figure
this out automatically when it sees a LUN greater than
0. Setting this flag only has the effect of telling the
driver to run the initial read capacity command for LUN
0 of the changer through the changer scheduling code.
FILES
/sys/bus/cam/scsi/scsi_cd.c is the driver source file.
SEE ALSOcd(4), scsi(4)HISTORY
The cd manual page first appeared in FreeBSD 2.2.
AUTHORS
This manual page was written by John-Mark Gurney ⟨gurney_j@efn.org⟩. It
was updated for CAM and FreeBSD 3.0 by Kenneth Merry ⟨ken@FreeBSD.org⟩.
BSD October 10, 1998 BSD
