[unix-history] / usr / src / share / man / man4 / man4.vax / ik.4

.\" Copyright (c) 1983, 1991, 1993
.\"	The Regents of the University of California.  All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)ik.4	8.1 (Berkeley) %G%
.\"
.Dd 
.Dt IK 4 vax
.Os BSD 4.2
.Sh NAME
.Nm ik
.Nd "Ikonas frame buffer, graphics device interface"
.Sh SYNOPSIS
.Cd "device ik0 at uba? csr 0172460 vector ikintr"
.Sh DESCRIPTION
The
.Nm ik
driver
provides an interface to an Ikonas frame buffer graphics device.
Each minor device is a different frame buffer interface board.
When the device is opened, its interface registers are mapped,
via virtual memory, into the user processes address space.
This allows the user process very high bandwidth to the frame buffer
with no system call overhead.
.Pp
Bytes written or read from the device are
.Tn DMA Ns 'ed
from or to the interface.
The frame buffer
.Tn XY
address, its addressing mode, etc. must be set up by the
user process before calling write or read.
.Pp
Other communication with the driver is via ioctls.
The
.Dv IK_GETADDR
.Xr ioctl 2
returns the virtual address where the user process can
find the interface registers.
The
.Dv IK_WAITINT
.Xr ioctl
suspends the user process until the ikonas device
has interrupted (for whatever reason \(em the user process has to set
the interrupt enables).
.Sh FILES
.Bl -tag -width /dev/ikxx -compact
.It Pa /dev/ik
.El
.Sh DIAGNOSTICS
None.
.Sh HISTORY
The
.Nm
driver appeared in
.Bx 4.2 .
.Sh BUGS
An invalid access (e.g., longword) to a mapped interface register
can cause the system to crash with a machine check.
A user process could possibly cause infinite interrupts hence
bringing things to a crawl.
Commit	Line	Data
5ebe7d4b KB	1	.\" Copyright (c) 1983, 1991, 1993
5ebe7d4b KB	2	.\" The Regents of the University of California. All rights reserved.
48234e1c	3	.\"
9903e566	4	.\" %sccs.include.redist.man%
48234e1c	5	.\"
5ebe7d4b	6	.\" @(#)ik.4 8.1 (Berkeley) %G%
9903e566 CL	7	.\"
	8	.Dd
	9	.Dt IK 4 vax
	10	.Os BSD 4.2
	11	.Sh NAME
	12	.Nm ik
	13	.Nd "Ikonas frame buffer, graphics device interface"
	14	.Sh SYNOPSIS
	15	.Cd "device ik0 at uba? csr 0172460 vector ikintr"
	16	.Sh DESCRIPTION
	17	The
	18	.Nm ik
	19	driver
48234e1c KM	20	provides an interface to an Ikonas frame buffer graphics device.
	21	Each minor device is a different frame buffer interface board.
	22	When the device is opened, its interface registers are mapped,
	23	via virtual memory, into the user processes address space.
	24	This allows the user process very high bandwidth to the frame buffer
	25	with no system call overhead.
9903e566 CL	26	.Pp
	27	Bytes written or read from the device are
	28	.Tn DMA Ns 'ed
	29	from or to the interface.
	30	The frame buffer
	31	.Tn XY
	32	address, its addressing mode, etc. must be set up by the
48234e1c	33	user process before calling write or read.
9903e566	34	.Pp
48234e1c	35	Other communication with the driver is via ioctls.
9903e566 CL	36	The
	37	.Dv IK_GETADDR
	38	.Xr ioctl 2
	39	returns the virtual address where the user process can
48234e1c	40	find the interface registers.
9903e566 CL	41	The
	42	.Dv IK_WAITINT
	43	.Xr ioctl
	44	suspends the user process until the ikonas device
48234e1c KM	45	has interrupted (for whatever reason \(em the user process has to set
48234e1c KM	46	the interrupt enables).
9903e566 CL	47	.Sh FILES
	48	.Bl -tag -width /dev/ikxx -compact
	49	.It Pa /dev/ik
	50	.El
	51	.Sh DIAGNOSTICS
48234e1c	52	None.
9903e566 CL	53	.Sh HISTORY
	54	The
	55	.Nm
	56	driver appeared in
	57	.Bx 4.2 .
	58	.Sh BUGS
48234e1c KM	59	An invalid access (e.g., longword) to a mapped interface register
	60	can cause the system to crash with a machine check.
	61	A user process could possibly cause infinite interrupts hence
	62	bringing things to a crawl.