====== Framebuffer ======

Graphics can be rendered using the linux framebuffer device, ''/dev/fb0''. By default the framebuffer is 800×480 with a B8G8R8A8 pixel order.

The framebuffer driver implements some special ''ioctl''s, [[https://github.com/nxp-imx/linux-imx/blob/lf-6.12.y/drivers/video/fbdev/mxc/mxc_ipuv3_fb.c|its source is available here]]. Some notable ones:

  * ''MXCFB_WAIT_FOR_VSYNC'' (''_IOW('F', 0x20, u_int32_t)'') blocks until vblank. The argument is ignored.
  * ''MXCFB_SET_GPU_SPLIT_FMT'' (''_IOW('F', 0x2F, struct mxcfb_gpu_split_fmt)'') seems to be used to setup triple-buffering (but how to use it properly?)