1.\" Copyright (c) 1997 2.\" John-Mark Gurney. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the author nor the names of any co-contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY John-Mark Gurney AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD$ 29.\" 30.Dd September 2, 2003 31.Dt CD 9 32.Os 33.Sh NAME 34.Nm cd 35.Nd CDROM driver for the CAM SCSI subsystem 36.Sh DESCRIPTION 37The 38.Nm 39device driver provides a read only interface for CDROM drives 40.Tn ( SCSI 41type 5) 42and WORM drives 43.Tn ( SCSI 44type 4) 45that support CDROM type commands. 46Some drives don't behave as the driver expects. See the section 47QUIRKS for info on possible flags. 48.Sh QUIRKS 49Each 50.Tn CD-ROM 51device can have different interpretations of the 52.Tn SCSI 53spec. This can lead to drives requiring special handling in the driver. The 54following is a list of quirks that the driver recognize. 55.Bl -tag -width CD_Q_BCD_TRACKS 56.It Dv CD_Q_NO_TOUCH 57This flag tell the driver not to probe the drive at attach time to see if 58there is a disk in the drive and find out what size it is. This flag is 59currently unimplemented in the CAM 60.Nm 61driver. 62.It Dv CD_Q_BCD_TRACKS 63This flag is for broken drives that return the track numbers in packed BCD 64instead of straight decimal. If the drive seems to skip tracks 65(tracks 10-15 are skipped) 66then you have a drive that is in need of this flag. 67.It Dv CD_Q_NO_CHANGER 68This flag tells the driver that the device in question is not a changer. 69This is only necessary for a CDROM device with multiple luns that are not a 70part of a changer. 71.It Dv CD_Q_CHANGER 72This flag tells the driver that the given device is a multi-lun changer. 73In general, the driver will figure this out automatically when it sees a 74LUN greater than 0. Setting this flag only has the effect of telling the 75driver to run the initial read capacity command for LUN 0 of the changer 76through the changer scheduling code. 77.It Dv CD_Q_10_BYTE_ONLY 78This flag tells the driver that the given device only accepts 10 byte MODE 79SENSE/MODE SELECT commands. In general these types of quirks should not be 80added to the 81.Xr cd 4 82driver. The reason is that the driver does several things to attempt to 83determine whether the drive in question needs 10 byte commands. First, it 84issues a CAM Path Inquiry command to determine whether the protocol that 85the drive speaks typically only allows 10 byte commands. (ATAPI and USB 86are two prominent examples of protocols where you generally only want to 87send 10 byte commands.) Then, if it gets an ILLEGAL REQUEST error back 88from a 6 byte MODE SENSE or MODE SELECT command, it attempts to send the 10 89byte version of the command instead. The only reason you would need a 90quirk is if your drive uses a protocol (e.g. 91.Tn SCSI ) 92that typically doesn't have a problem with 6 byte commands. 93.El 94.Sh FILES 95.Bl -tag -width /sys/cam/scsi/scsi_cd.c -compact 96.It Pa /sys/cam/scsi/scsi_cd.c 97is the driver source file. 98.El 99.Sh SEE ALSO 100.Xr cd 4 , 101.Xr scsi 4 102.Sh HISTORY 103The 104.Nm 105manual page first appeared in 106.Fx 2.2 . 107.Sh AUTHORS 108.An -nosplit 109This 110manual page was written by 111.An John-Mark Gurney Aq gurney_j@efn.org . 112It was updated for CAM and 113.Fx 3.0 114by 115.An Kenneth Merry Aq ken@FreeBSD.org . 116