NAME

     atapicam — CAM XPT (transport) module for ATAPI devices

SYNOPSIS

     To compile this driver into the kernel, place the following lines in your kernel
     configuration file:

           device scbus
           device ata
           device atapicam

     Alternatively, to load the driver as a module at boot time, place the following line in
     loader.conf(5):

           atapicam_load="YES"

DESCRIPTION

     The ATAPI/CAM module allows ATAPI devices (CD-ROM, CD-RW, DVD drives, floppy drives such as
     Iomega Zip, tape drives) to be accessed through the SCSI subsystem, cam(4).

     ata(4) and scbus(4) must be configured in the kernel as well.  The SCSI target drivers
     (cd(4), da(4), or st(4)) can then be used to access the devices.  The generic passthrough
     device, pass(4), can also be used to send SCSI commands directly to the devices through the
     CAM API.

     A separate CAM bus is created for each ATA bus in the system.  On each of these buses,
     target ID 0 is assigned to the master device, and ID 1 is assigned to the slave (provided
     they are ATAPI devices).

IMPLEMENTATION NOTES

     Some SCSI commands are intercepted by the driver, and undergo special processing in order to
     work around limitations of ATAPI devices.  Such limitations can be consequences of the ATAPI
     specification.  For example, ATAPI devices do not implement the 6-byte versions of
     MODE_SELECT, MODE_SENSE, READ, or WRITE.  They can also be common bugs, such as hanging when
     queried for extended INQUIRY information.

EXAMPLES

           device ata
           device atapicam
           device scbus
           device cd
           device pass

     Add the atapicam driver to the kernel.

           camcontrol devlist

     Print the list of all devices available through CAM.

           mount -t cd9660 /dev/cd0 /mnt

     Mount a CD-ROM from an ATAPI CD-ROM drive (the command above assumes that the ATAPI drive is
     the only CD-ROM unit).

SEE ALSO

     ata(4), cam(4), scsi(4), atacontrol(8), camcontrol(8)

HISTORY

     The ATAPI/CAM driver first appeared in FreeBSD 4.8 and FreeBSD 5.0.

AUTHORS

     The ATAPI/CAM driver was written by Thomas Quinot <thomas@FreeBSD.org>.

BUGS

     atapicam and ATAPI-specific target drivers (acd(4), ast(4), and afd(4)) can be configured in
     the same kernel.  Simultaneous access to the same device through the SCSI generic drivers
     and the ATAPI-specific drivers may cause problems and is strongly discouraged.