NAME
natapicam
—
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 nata
device natapicam
Alternatively, to load the driver as a module at boot time, place the following line in loader.conf(5):
natapicam_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).nata(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 nata device natapicam device scbus device cd device pass
Add the natapicam
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
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
natapicam
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.