public FbDevBackBuffer(int fb, fb_fix_screeninfo fixedInfo, fb_var_screeninfo varInfo, IntPtr targetAddress)
 {
     _fb            = fb;
     _fixedInfo     = fixedInfo;
     _varInfo       = varInfo;
     _targetAddress = targetAddress;
     Address        = Marshal.AllocHGlobal(RowBytes * Size.Height);
 }
 public static extern int ioctl2(
     [MarshalAs(UnmanagedType.I4)] int filedes,
     [MarshalAs(UnmanagedType.I4)] int command,
     ref fb_var_screeninfo data
     );