NAME    [Toc]    [Back]

     agp -- generic interface to the Accelerated Graphics Port (AGP)

SYNOPSIS    [Toc]    [Back]

     device agp

DESCRIPTION    [Toc]    [Back]

     The agp driver provides uniform, abstract methods for controlling the
     following devices:
	   +o   Ali M1541 host-to-AGP bridge
	   +o   AMD 751 and 761 host-to-AGP bridges
	   +o   Intel i820, i840, i845, i850, and i860 host-to-AGP bridge
	   +o   Intel i810, i810-DC100, i810E, and i815 SVGA controllers
	   +o   Intel 82443GX host-to-AGP bridge
	   +o   SiS 5591 host-to-AGP bridge

     The most common application of agp is for running XFree86(1) on the Intel
     i81x controllers.

IOCTLS    [Toc]    [Back]

     The following ioctl(2) operations can be performed on /dev/agpgart, which
     are defined in <sys/agpio.h>:

     AGPIOC_INFO
	     Returns state of the agp system.  The result is a pointer to the
	     following structure:

	     typedef struct _agp_info {
		     agp_version version;  /* version of the driver	   */
		     u_int32_t bridge_id;  /* bridge vendor/device	   */
		     u_int32_t agp_mode;   /* mode info of bridge	   */
		     off_t aper_base;	   /* base of aperture		   */
		     size_t aper_size;	   /* size of aperture		   */
		     size_t pg_total;	   /* max pages (swap + system)    */
		     size_t pg_system;	   /* max pages (system)	   */
		     size_t pg_used;	   /* current pages used	   */
	     } agp_info;

     AGPIOC_ACQUIRE
	     Acquire control of the AGP chipset for use by this client.
	     Returns EBUSY if the AGP chipset is already acquired by another
	     client.

     AGPIOC_RELEASE
	     Release control of the AGP chipset.  This does not unbind or free
	     any allocated memory, which is the responsibility of the client
	     to handle if necessary.

     AGPIOC_SETUP
	     Enable the AGP hardware with the relevant mode.  This ioctl(2)
	     takes the following structure:

	     typedef struct _agp_setup {
		     u_int32_t agp_mode;   /* mode info of bridge */
	     } agp_setup;

	     The mode bits are defined in <sys/agpio.h>.

     AGPIOC_ALLOCATE
	     Allocate physical memory suitable for mapping into the AGP aperture.
  This ioctl(2) takes the following structure:

	     typedef struct _agp_allocate {
		     int key;		   /* tag of allocation 	   */
		     size_t pg_count;	   /* number of pages		   */
		     u_int32_t type;	   /* 0 == normal, other devspec   */
		     u_int32_t physical;   /* device specific (some devices
					    * need a phys address of the
					    * actual page behind the gatt
					    * table)			   */
	     } agp_allocate;

	     Returns a handle to the allocated memory.

     AGPIOC_DEALLOCATE
	     Free the previously allocated memory associated with the handle
	     passed.

     AGPIOC_BIND
	     Bind the allocated memory at given offset with the AGP aperture.
	     Returns EINVAL if the memory is already bound or the offset is
	     not at AGP page boundary.	This ioctl(2) takes the following
	     structure:

	     typedef struct _agp_bind {
		     int key;	      /* tag of allocation	      */
		     off_t pg_start;  /* starting page to populate    */
	     } agp_bind;

	     The tag of allocation is the handle returned by AGPIOC_ALLOCATE.

     AGPIOC_UNBIND
	     Unbind memory from the AGP aperture.  Returns EINVAL if the memory
 is not bound.	This ioctl(2) takes the following structure:

	     typedef struct _agp_unbind {
		     int key;		     /* tag of allocation	  */
		     u_int32_t priority;     /* priority for paging out   */
	     } agp_unbind;

FILES    [Toc]    [Back]

     /dev/agpgart  AGP device node.

SEE ALSO    [Toc]    [Back]

     XFree86(1)

HISTORY    [Toc]    [Back]

     The agp driver first appeared in FreeBSD 4.1.


FreeBSD 5.2.1			October 5, 2001 		 FreeBSD 5.2.1