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 do not behave as the driver expects. 47See the 48.Sx QUIRKS 49section for information on possible flags. 50.Sh QUIRKS 51Each 52.Tn CD-ROM 53device can have different interpretations of the 54.Tn SCSI 55spec. 56This can lead to drives requiring special handling in the driver. 57The following is a list of quirks that the driver recognize. 58.Bl -tag -width CD_Q_BCD_TRACKS 59.It Dv CD_Q_NO_TOUCH 60This flag tell the driver not to probe the drive at attach time to see if 61there is a disk in the drive and find out what size it is. 62This flag is currently unimplemented in the CAM 63.Nm 64driver. 65.It Dv CD_Q_BCD_TRACKS 66This flag is for broken drives that return the track numbers in packed BCD 67instead of straight decimal. 68If the drive seems to skip tracks 69(tracks 10-15 are skipped) 70then you have a drive that is in need of this flag. 71.It Dv CD_Q_NO_CHANGER 72This flag tells the driver that the device in question is not a changer. 73This is only necessary for a CDROM device with multiple luns that are not a 74part of a changer. 75.It Dv CD_Q_CHANGER 76This flag tells the driver that the given device is a multi-lun changer. 77In general, the driver will figure this out automatically when it sees a 78LUN greater than 0. 79Setting this flag only has the effect of telling the 80driver to run the initial read capacity command for LUN 0 of the changer 81through the changer scheduling code. 82.It Dv CD_Q_10_BYTE_ONLY 83This flag tells the driver that the given device only accepts 10 byte MODE 84SENSE/MODE SELECT commands. 85In general these types of quirks should not be 86added to the 87.Xr cd 4 88driver. 89The reason is that the driver does several things to attempt to 90determine whether the drive in question needs 10 byte commands. 91First, it 92issues a CAM Path Inquiry command to determine whether the protocol that 93the drive speaks typically only allows 10 byte commands. 94(ATAPI and USB 95are two prominent examples of protocols where you generally only want to 96send 10 byte commands.) 97Then, if it gets an ILLEGAL REQUEST error back 98from a 6 byte MODE SENSE or MODE SELECT command, it attempts to send the 10 99byte version of the command instead. 100The only reason you would need a 101quirk is if your drive uses a protocol (e.g., 102.Tn SCSI ) 103that typically does not have a problem with 6 byte commands. 104.El 105.Sh FILES 106.Bl -tag -width /sys/cam/scsi/scsi_cd.c -compact 107.It Pa /sys/cam/scsi/scsi_cd.c 108is the driver source file. 109.El 110.Sh SEE ALSO 111.Xr cd 4 , 112.Xr scsi 4 113.Sh HISTORY 114The 115.Nm 116manual page first appeared in 117.Fx 2.2 . 118.Sh AUTHORS 119.An -nosplit 120This 121manual page was written by 122.An John-Mark Gurney Aq gurney_j@efn.org . 123It was updated for CAM and 124.Fx 3.0 125by 126.An Kenneth Merry Aq ken@FreeBSD.org . 127