IK
Section: Devices and Network Interfaces (4)
Updated: vax
Index
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BSD mandoc
BSD 4.2
NAME
ik
- Ikonas frame buffer, graphics device interface
SYNOPSIS
device ik0 at uba? csr 0172460 vector ikintr
DESCRIPTION
The
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.
Bytes written or read from the device are
DMA 'ed
from or to the interface.
The frame buffer
XY
address, its addressing mode, etc. must be set up by the
user process before calling write or read.
Other communication with the driver is via ioctls.
The
IK_GETADDR
ioctl(2)
returns the virtual address where the user process can
find the interface registers.
The
IK_WAITINT
ioctl
suspends the user process until the ikonas device
has interrupted (for whatever reason --- the user process has to set
the interrupt enables).
FILES
- /dev/ik
-
DIAGNOSTICS
None.
HISTORY
The
driver appeared in
BSD 4.2
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.
Index
- NAME
-
- SYNOPSIS
-
- DESCRIPTION
-
- FILES
-
- DIAGNOSTICS
-
- HISTORY
-
- BUGS
-
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Time: 06:48:41 GMT, May 19, 2025