NAME

bwtwo − Sun-3/Sun-2 black and white frame buffer

SYNOPSIS — SUN-3

device bwtwo0 at obmem 1 csr 0xff000000 priority 4
device bwtwo0 at obmem 2 csr 0x100000 priority 4
device bwtwo0 at obmem 3 csr 0xff000000 priority 4
device bwtwo0 at obmem 4 csr 0xff000000

The first synopsis line given above should be used to generate a kernel for a Sun-3/75 or Sun-3/160; the second, for a Sun-3/50; the third, for a Sun-3/260; and the fourth, for a Sun-3/110. 

SYNOPSIS — SUN-2

device bwtwo0 at obmem 1 csr 0x700000 priority 4
device bwtwo0 at obio 2 csr 0x0 priority 4

The first synopsis line given above should be used to generate a kernel for a Sun-2/120 or Sun-2/170; the second, for a Sun-2/50 or Sun-2/160. 

DESCRIPTION

The bwtwo interface provides access to Sun monochrome memory frame buffers.  It supports the ioctls described in fbio(4S).

If flags 0x1 is specified, frame buffer write operations are buffered through regular high-speed RAM.  This “copy memory” mode of operation speeds frame buffer accesses, but consumes an extra 128K bytes of memory.  Only the Sun-3/50, Sun-3/75, and Sun-3/160 support copy memory; on other systems a warning message will be printed and the flag will be ignored. 

Reading or writing to the frame buffer is not allowed — you must use the mmap(2) system call to map the board into your address space.

FILES

/dev/bwtwo[0-9]

SEE ALSO

mmap(2), fb(4S), fbio(4S), cgfour(4S)

BUGS

Use of vertical-retrace interrupts is not supported. 
 

Sun Release 3.5  —  Last change: 16 January 1987