agp(4)

NAME

agp - generic interface to the Accelerated Graphics Port

(AGP)

SYNOPSIS

device agp

DESCRIPTION

The agp driver provides uniform, abstract methods for con

trolling the
following devices:

ALI: M1541, M1621 and M1671 host to AGP bridges
AMD: 751, 761 and 762 host to AGP bridges
ATI: RS100, RS200, RS250 and RS300 AGP bridges
Intel: i820, i840, i845, i850, and i860 host to AGP bridge
Intel: i810, i810-DC100, i810E, i815, 830M, 845G, 852GM,

852GME, 855GM,

855GME, 865G, 915G and 915GM SVGA controllers

Intel: 82443BX, 82443GX, 82443LX, 82815, 82820, 82830,

82840, 82845,

82845G, 82850, 82855, 82855GM, 82860, 82865, 82875P

and E7205
host to AGP bridges

NVIDIA: nForce and nForce2 AGP controllers
SiS: 530, 540, 550, 620, 630, 645, 645DX, 648, 650, 651,

655, 661,

730, 735, 740, 741, 745, 746, 760 and 5591 host to

AGP bridges

VIA: 3296, 82C597, 82C598, 82C691, 82C694X, 82C8363,

8235, 8237,

8361, 8367, 8371, 8377, 8501, 8601, 862x, 8633,

8653, 8703,
8753, 8754, 8763, 8783, KT880, PM800, PM880, PN800,

PN880,
PT880, XM266 and XN266 host to PCI bridges

The most common application of agp is for running X(7) on

the Intel i81x
controllers.

IOCTLS

The following ioctl(2) operations can be performed on

/dev/agpgart, which
are defined in

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/de

vice */
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

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 popu

late */

} agp_bind;

The tag of allocation is the handle returned by AG

PIOC_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 pag

ing out */

} agp_unbind;

FILES

/dev/agpgart AGP device node.

SEE ALSO

X(7) (ports/x11/xorg)

HISTORY

The agp driver first appeared in FreeBSD 4.1.

BSD December 20, 2005

BSD