cgfour(7D)
NAME
cgfour - P4-bus 8-bit color memory frame buffer
SYNOPSIS
/dev/fbs/cgfourn
DESCRIPTION
The cgfour is a color memory frame buffer with a monochrome
overlay plane and an overlay enable plane. It provides the
standard frame buffer interface as defined in fbio(7I).
In addition to the ioctls described under fbio(7I) the
cgfour interface responds to two cgfour-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 cgfour has an overlay plane colormap, which is accessed
by encoding the plane group into the index value with the
PIX_GROUP macro (see <sys/pr_planegroups.h>).
FILES
/dev/fbs/cgfour0
SEE ALSO
mmap(2), fbio(7I)
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