Technical data

SunOS 5.5 Devices cgeight(7D)
NAME cgeight − 24-bit color memory frame buffer
SYNOPSIS /dev/fbs/cgeightn
DESCRIPTION The cgeight is a 24-bit color memory frame buffer with a monochrome overlay plane and
an overlay enable plane implemented optionally on the Sun-4/110, Sun-4/150, Sun-4/260
and Sun-4/280 system models. It provides the standard frame buffer interface as defined
in fbio(7I).
In addition to the ioctls described under fbio(7I), the cgeight interface responds to two
cgeight-specific colormap ioctls, FBIOPUTCMAP and FBIOGETCMAP. FBIOPUTCMAP
returns no information other than success/failure using the ioctl return value.
FBIOGETCMAP returns its information in the arrays pointed to by the red, green, and
blue members of its fbcmap structure argument; fbcmap is defined in <sys/fbio.h> as:
struct fbcmap {
int index; /∗ first element (0 origin) ∗/
int count; /∗ number of elements ∗/
unsigned char ∗red; /∗ red color map elements ∗/
unsigned char ∗green; /∗ green color map elements ∗/
unsigned char ∗blue; /∗ blue color map elements ∗/
};
The driver uses color board vertical-retrace interrupts to load the colormap.
The systems have an overlay plane colormap, which is accessed by encoding the plane
group into the index value with thePIX_GROUP macro (see <sys/pr_planegroups.h>).
When using the mmap(2) system call to map in the cgeight frame buffer. The device
looks like:
DACBASE: 0x200000 -> Brooktree Ramdac 16 bytes
0x202000 -> P4 Register 4 bytes
OVLBASE: 0x210000 -> Overlay Plane 1152x900x1
0x230000 -> Overlay Enable Planea 1152x900x1
0x250000 -> 24-bit Frame Buffera 1152x900x32
FILES /dev/fbs/cgeight0
<sys/fbio.h>
<sys/pr_planegroups.h>
SEE ALSO mmap(2), fbio(7I)
modified 27 Mar 1992 7D-61