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TARG(4)		       FreeBSD Kernel Interfaces Manual		       TARG(4)

NAME
     targ -- SCSI target emulator driver

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

	   device targ

DESCRIPTION
     The targ driver provides an interface for usermode	programs to emulate
     SCSI target devices.  A sample program that emulates a disk drive (simi-
     lar to da(4)) can be found	in /usr/share/examples/scsi_target.

     The targ driver supplies the control device /dev/targ.  After opening the
     device, the file descriptor must be bound to a specific bus/target/LUN
     and enabled to process CCBs using the TARGIOCENABLE ioctl.	 The process
     then uses write(2)	to send	CCBs to	the SIM	and poll(2) or kqueue(2) to
     see if responses are ready.  Pointers to completed	CCBs are returned via
     read(2).  Any data	transfers requested by the user	CCBs are done via
     zero-copy IO.

IOCTLS
     The following ioctl(2) calls are defined in the header file
     <cam/scsi/scsi_targetio.h>.

     TARGIOCENABLE   (struct ioc_enable_lun) Enable target mode	on the LUN
		     specified by the following	structure:

			   struct ioc_enable_lun {
				   path_id_t	   path_id;
				   target_id_t	   target_id;
				   lun_id_t	   lun_id;
				   int		   grp6_len;
				   int		   grp7_len;
			   };

		     The selected path (bus), target, and LUN must not already
		     be	in use or EADDRINUSE is	returned.  If grp6_len or
		     grp7_len are non-zero, reception of vendor-specific com-
		     mands is enabled.

     TARGIOCDISABLE  Disable target mode and abort all pending CCBs.  The CCBs
		     may optionally be read as they complete.  TARGIOCENABLE
		     can then be called	to activate a different	LUN.  Multiple
		     disable calls have	no effect.  The	close(2) system	call
		     automatically disables target mode	if enabled.

     TARGIOCDEBUG    (int) Enables CAM_PERIPH debugging	if the argument	is
		     non-zero, otherwise disables it.

FILES
     <cam/scsi/scsi_targetio.h>	  describes the	usermode interface.
     /sys/cam/scsi/scsi_target.c  is the driver	source file.
     /dev/targ			  is the control device.

SEE ALSO
     /usr/share/examples/scsi_target, ahc(4), isp(4), scsi(4)

     FreeBSD Target Information, http://www.root.org/~nate/freebsd/.

AUTHORS
     The targ driver first appeared in FreeBSD 3.0 and was written by Justin
     T.	Gibbs.	It was rewritten for FreeBSD 5.0 by Nate Lawson
     <nate@root.org>.

BUGS
     Currently,	only the ahc(4)	and isp(4) drivers fully support target	mode.

     The ahc(4)	driver does not	support	tagged queuing in target mode.

FreeBSD	10.1		       December	13, 2011		  FreeBSD 10.1

NAME | SYNOPSIS | DESCRIPTION | IOCTLS | FILES | SEE ALSO | AUTHORS | BUGS

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