As it's memory mapped, the display is *not* accessed like a file. The display becomes part of user-space memory. You could "intercept" it by having another display device in kernel.

The display device is also synchronised to audio in the kernel: there are multiple display buffers and the display is flipped by teh audio DMA requests in kernel (the player doesn't get involved). This may change in the future though, there are other plans afoot...

Hugo