NAME

cgfour − Sun-3 color memory frame buffer

CONFIG — SUN-3 SYSTEM

device cgfour0 at obmem 4 csr 0xff000000 priority 4
device cgfour0 at obmem 7 csr 0xff000000 priority 4

The first synopsis line given should be used to generate a kernel for the Sun-3/110 system; the second, for a Sun-3/60 system. 

DESCRIPTION

The cgfour is a color memory frame buffer with a monochrome overlay plane and an overlay enable plane implemented on the Sun-3/110 system and some Sun-3/60 system models.  It provides the standard frame buffer interface as defined in fbio(4S). 

In addition to the ioctls described under fbio(4S), 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 <sun/fbio.h> as:

struct fbcmap {
intindex;/∗ first element (0 origin) ∗/
intcount;/∗ 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 Sun-3/60 system has an overlay plane colormap, which is accessed by encoding the plane group into the index value with the PIX_GROUP macro (see <pixrect/pr_planegroups.h>). 

FILES

/dev/cgfour0

SEE ALSO

mmap(2), fbio(4S)

Sun Release 4.0  —  Last change: 9 October 1987