Does anyone know where this function is implemented?

I've looked at all the scripts in /etc/init.d/, in the initrd (/linuxrc, /etc/init, etc).. but
cannot locate it anywhere. Specifically, what generates that blue screen
that says:

Knoppix has found an image file. Please
be aware of the potential security risk of such configuration images,
because of scripts that can...

Acknowledge image activation by selecting OK. If you do nothing, the
system will boot normally (without image activation) in 20 seconds

KNOPPIX-CONFIGURATION
x home Mount persistent knoppix-homedirectory
x system Add as persistent, writable system area
x overwrite overwrite/update stored system configuration in image
x init start INIT-bootscripts (network, printer, etc.)

I understand the purpose of the screen and the options, I just cannot
locate where this is all implemented. Can anyone shed some light on this?