.\" Copyright (c) 1990, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" This code is derived from software contributed to Berkeley by
.\" the Systems Programming Group of the University of Utah Computer
.\" Science Department.
.\" %sccs.include.redist.man%
.\"
.\"     @(#)grf.4	5.2 (Berkeley) 03/27/91
.\"
.Dd 
.Dt GRF 4 hp300
.Os
.Sh NAME
.Nm grf
.Nd
.Tn HP
graphics frame buffer device interface
.Sh DESCRIPTION
This is a generic description of the frame buffer device interface.
The devices to which this applies are the 98544, 98545 and 98547
Topcat display cards (also known as
.Tn HP300H
devices),
the 98548, 98549 and 98550
Catseye display cards,
the 98700
Gatorbox graphics box,
the 98720
Renaissance graphics box,
and the 98730
DaVinci graphics box.
.Pp
Use of the devices can be effectively approached from two directions.
The first is through
.Tn HP-UX
.Em Starbase
routines, the second is by direct control in the
.Bx
environment.
In order to use the Starbase libraries,
code must be compiled in an
.Tn HP-UX
environment, either by doing so on an
.Tn HP-UX
machine and transferring the binaries to the
.Bx
machine, or by compilation
with the use of the
.Xr hpux 1
command.
Applications using Starbase libraries have been run successfully
on
.Bx
machines using both of these compilation techniques.
.Pp
Direct compilation,
such as that used for the X Window System servers, has also been successful.
Examples of some frame buffer operations can be found in
the device dependent X Window system sources, for example the
.Pa /usr/src/new/X/libhp.fb
directory.  These files contain examples of device dependent color map
initialization, frame buffer operations, bit moving routines etc.
.Pp
The basic programming of the
.Nm grf Ns Em \?
devices involves opening the device
file, mapping the control registers and frame buffer addresses into user
space, and then manipulating the device as the application requires.
The address mapping is controlled by an
.Xr ioctl 2
call to map the device into user space, and an unmap call when finished.
The ioctls supported by
.Bx
are:
.Bl -tag -width indent
.It Dv GRFIOCGINFO
Get Graphics Info
.Pp
Get info about device, setting the entries in the
.Em grfinfo
structure, as defined in <hpdev/grfioctl.h>:
.Bd -literal
struct	grfinfo {
	int	gd_id;		/* HPUX identifier */
	caddr_t	gd_regaddr;	/* control registers physaddr */
	int	gd_regsize;	/* control registers size */
	caddr_t	gd_fbaddr;	/* frame buffer physaddr */
	int	gd_fbsize;	/* frame buffer size */
	short	gd_colors;	/* number of colors */
	short	gd_planes;	/* number of planes */
/* new stuff */
	int	gd_fbwidth;	/* frame buffer width */
	int	gd_fbheight;	/* frame buffer height */
	int	gd_dwidth;	/* displayed part width */
	int	gd_dheight;	/* displayed part height */
	int	gd_pad[6];	/* for future expansion */
};
.Ed
.It Dv GRFIOCON
Graphics On
.Pp
Turn graphics on by enabling
.Tn CRT
output.  The screen will come on, displaying
whatever is in the frame buffer, using whatever colormap is in place.
.It Dv GRFIOCOFF
Graphics Off
.Pp
Turn graphics off by disabling output to the
.Tn CRT .
The frame buffer contents
are not affected.
.It Dv GRFIOCMAP
Map Device to user space
.Pp
Map in control registers and framebuffer space. Once the device file is
mapped, the frame buffer structure is accessible.
.It Dv GRFIOCUNMAP
Unmap Device
.Pp
Unmap control registers and framebuffer space.
.El
.Pp
For further information about the use of ioctl see the man page.
.Sh EXAMPLE
This short code fragment is an example of opening some graphics device and
mapping in the control and frame buffer space:
.Bd -literal
#define GRF_DEV <some_graphics_device>  /* /dev/grfN */
{
	struct fbstruct *regs;  /*  fbstruct = gboxfb, rboxfb, etc. */
	u_char *Addr, frame_buffer;
	struct grfinfo gi;
	int disp_fd;

	disp_fd = open(GRF_DEV,1);
	if (ioctl (disp_fd, GRFIOCGINFO, &gi) < 0) return -1;
	(void) ioctl (disp_fd, GRFIOCON, 0);

	Addr = (u_char *) 0;
	if (ioctl (disp_fd, GRFIOCMAP, &Addr) < 0) {
		(void) ioctl (disp_fd, GRFIOCOFF, 0);
		return -1;
	}
	regs = (fbstruct *) Addr;               /* Control Registers   */
	frame_buffer = (u_char *) Addr + gi.gd_regsize; /* Frame buffer mem */
}
.Ed
.Sh FILES
.Bl -tag -width /dev/*crt*? -compact
.It Pa /dev/grf?
.Bx
interface special files
.It Pa /dev/*crt*
.Tn HP-UX
.Em starbase
interface special files
.El
.Sh DIAGNOSTICS
None under
.Bx .
.Tn HP-UX
The
.Tn CE.utilities/Crtadjust
programs must be used for each specific device.
.Sh ERRORS
.Bl -tag -width [EINVAL]
.It Bq Er ENODEV
no such device.
.It Bq Er EBUSY
Another process has the device open.
.It Bq Er EINVAL
Invalid ioctl specification.
.El
.Sh SEE ALSO
.Xr ioctl 2 ,
.Xr dv 4 ,
.Xr gb 4 ,
.Xr rb 4 ,
.Xr tc 4 ,
.Xr hil 4
.Sh HISTORY
The
.Nm
driver
.Ud