the use of FBdriver

the use of  FBdriver

first open a device file,open("/dev/fb0",O_RDWR)

then make a vinfo,ioctl(*p,FBIOGET_VSCREENINFO,&vinfo)

then get the  vinfo's size to a buffer;

then,mmap the buffer

then,memset the value

then,munmap

then,close the file

the whole step is all .