[gdm-list] gdm: daemons affecting Xorg display configuration and evdev touch screen calibration

[Björn Gerhart <gerhart posteo de>]

Dear list,

I’m using gdm-3.14 with CentOS 7. On my system, I don’t provide a static /etc/X11/xorg.conf. Two displays are 
connected, one of the displays is equipped with a touch screen by eGalax, which is compatible to evdev.

When running gdm and gnome-shell, which is the default after el7 installation, the displays get arranged in 
the style of the formerly „Xinerama“ automatically. So when I move the mouse to the right border of one 
display, the cursor will appear on the left border of the other display. Furthermore, the touch screen gets 
configured exactly the way as expected - the mouse cursor is located directly under the finger of the display 
which is eqipped with the touch screen.

Now, when I simply type „xinit“ instead from the active multi-user target (according to formerly „runlevel 
3“), both displays show the same content (mirroring). But I want the simple „xinit“ to behave the same way 
like gnome does - for dynamically configuring the displays and evdev behavior.

Which are the daemons or the functionality behind the gdm resp. gnome startup mechanism, providing that 
behavior? I want xinit to start these separately without gnome-shell, and I wonder how to achieve that.

Best - Björn