The X Window System Frame Buffer Specific DDX Module
When the X Window System exits to the command line, the frame
buffer's DDX module must send an ioctl to the frame buffer driver. This ioctl
triggers the frame buffer driver to call the terminal emulator's mode change callback
function. This communication keeps the frame buffer driver and the terminal emulator in
agreement about the video mode if the X Window System starts and then
changes the video resolution before exiting. The frame buffer driver and the
terminal emulator must agree about the video mode at all times. When the
frame buffer driver and the terminal emulator do not agree about the video
mode, the information on the screen is illegible and meaningless.
