1.Dd August 27, 1993 2.Dt CD 4 3.Os FreeBSD 4.Sh NAME 5.Nm cd 6.Nd scsi cdrom driver 7.Sh SYNOPSIS 8.Nm device cd 9.Nm device cd1 target 4 lun 0 10.Sh DESCRIPTION 11The 12.Xr cd 13driver provides support for a 14.Em scsi 15cdrom. It allows the cdrom 16to be divided up into a set of pseudo devices called 17.Em partitions. 18In an attempt to look like regular disks the 19.Nm 20driver synthesises a partition table, with one partition covering the entire 21cdrom. A user might (for some amazing reason) add another partition to the 22cdrom by using disklabel, but it will last only until the cdrom is unmounted. 23A Partition can have both a 24.Em raw 25interface 26and a 27.Em Block mode 28interface. 29In general the interfaces are similar to those described by 30.Xr wd 4 31or 32.Xr sd 4 . 33 34.Pp 35Where the 36.Xr wd 4 37device has a fairly low level interface to the system, 38.Em SCSI 39devices have a much higher level interface and talk to the system via 40a 41.Em SCSI Adapter 42and a 43.Em Scsi Adapter driver 44e.g. 45.Xr AHA1542 . 46A scsi adapter must also be separatly configured into the system 47before a scsi cdrom can be configured. 48.Pp 49As the scsi adapter is probed during boot, the 50.Em SCSI 51bus is scanned for devices. Any devices found which answer as 'Readonly' 52type devices will be 'attached' to the 53.Nm 54driver. 55In FreeBSD releases prior to 2.1, the first found will be attached as 56.Em cd0 57and the next, 58.Em cd1 59etc. 60Beginning in 2.1 it is possible to specify what cd unit a device should 61come on line as; refer to 62.Xr scsi 4 63for details on kernel configuration. 64.Pp 65The system utility 66.Xr disklabel 1 67may be used to read the synthesized 68.Xr disklabel 5 69structure, which will contain correct figures for the size of the cdrom 70should that information be required. 71.Pp 72.Sh KERNEL CONFIGURATION 73Any number of cdroms may be attached to the system regardless of system 74configuration as all resources are dynamically allocated. 75 76.Pp 77.Sh IOCTLS 78The following 79.Xr ioctl 2 80calls apply to scsi cdroms 81in the header files 82.Em sys/cdio.h. 83and 84.Em sys/disklabel.h 85 86.Bl -tag -width CDIOCPLAYAUDIO____ 87 88.It Dv DIOCGDINFO 89Read, from the kernel, the in-core copy of the disklabel for the 90drive. This will be a ficticious disklabel it will contain information 91read from the scsi inquiry commands, and should be the same as 92the information printed at boot. 93.It Dv DIOCSDINFO 94Give the driver a new disklabel to use. The driver will NOT try write the new 95disklabel to the disk. (ok?) 96.It CDIOCPLAYTRACKS 97Start Audio playback given a track address and length. 98.It CDIOCPLAYBLOCKS 99Start Audio playback given a block address and length. 100.It CDIOCPLAYMSF 101Start Audio playback given a 'Minutes/ seconds/ frames' address and length. 102.It CDIOCREADSUBCHANNEL 103Read information from the subchannel at the location specified. 104.It CDIOREADTOCHEADER 105Return summary information about the table of contents for the mounted cdrom. 106.It CDIOREADTOCENTRYS 107Return information from the table of contents entries mentionned. 108.It CDIOCSETPATCH 109Attach various audio channels to various output channels. 110.It CDIOCGETVOL 111Get information about the volume settings of the output channels. 112.It CDIOCSETVOL 113Change the volume settings of the output channels. 114.It CDIOCSETMONO 115Patch all out[put channels to all source channels. 116.It CDIOCSETSTERIO 117Patch left source channel to the left output channel and the right 118source channel to the right output channel. 119.It CDIOCSETMUTE 120Mute output without changing the volume settings. 121.It CDIOCSETLEFT 122Attach both output channels to the left source channel. 123.It CDIOCSETRIGHT 124Attach both output channels to the right source channel. 125.It CDIOCSETDEBUG 126Turn on debugging for the appropriate device. 127.It CDIOCCLRDEBUG 128Turn off debugging for the appropriate device. 129.It CDIOCPAUSE 130Pause audio play, do not reset the location of the read-head. 131.It CDIOCRESUME 132Resume audio play, Start at the location of the pause. 133.It CDIOCRESET 134Reset the drive. 135.It CDIOCSTART 136Tell the drive to spin-up the cdrom. 137.It CDIOCSTOP 138Tell the drive to spin-down the cdrom. 139.It CDIOCEJECT 140Eject the cdrom. 141.El 142.Pp 143In addition the general 144.Xr scsi 4 145ioctls may be used with the 146.Nm 147driver, if used against the fourth (raw/whole disk) partiton. (e.g. rcd0d) 148.Sh NOTES 149When a cdrom is changed in a drive controlled by the 150.Nm 151driver, then the act of changing the media will invalidate the 152disklabel and information held within the kernel. To stop corruption, 153All accesses to the device will be discarded until there are no more 154open file descriptors referencing the device. During this period, all 155new open attempts will be rejected. When No more open file descriptors 156reference the device, the first next open will load a new set of 157figures (including disklabel) for the drive. 158 159The Audio code in the 160.Nm 161driver only support SCSI2 standard audio commands. As there are many cdrom 162manufacturers who have not followed the standard well, there are many 163cdroms for which audio will not work. Some work is planned to support 164some of the more common 'broken' cdrom drives however this is not yet 165under way. 166 167.Sh FILES 168.Bl -tag -width /dev/rcd[0-9][a-h] -compact 169.It Pa /dev/cd[0-9][a-h] 170block mode scsi disks 171.It Pa /dev/rcd[0-9][a-h] 172raw scsi disks 173.El 174.Sh DIAGNOSTICS 175None. 176.Sh SEE ALSO 177.Xr disklabel 1 178.Xr disklabel 5 179.Xr wd 4 180.Xr sd 4 181.Sh HISTORY 182This 183.Nm 184driver appeared in 386BSD 0.1. 185