NAME

cgeight - 24-bit color memory frame buffer

SYNOPSIS

/dev/fbs/cgeight

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(7).

In addition to the ioctls described under fbio(7), 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 the PIX_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(7)