I have a custom preseed file for a Precise Live CD (which is well loaded on boot, I checked syslog for that).
My initial problem is that when booting in install mode (default behavior for a Live CD), ubiquity runs X with a default wallpaper which is hardcoded to /usr/share/backgrounds/warty-final-ubuntu.png in Ubiquity code.
So my idea was to run early_command (https://help.ubuntu.com/12.04/installation-guide/i386/preseed-advanced.html) to copy my custom wallpaper over /usr/share/backgrounds/warty-final-ubuntu.png.
Assuming my custom wallpaper allready resides on the rootfs in /usr/share/backgrounds.
But... It seems the early_command never runs (and I'm sure the preseed file is taken into account)
Here is what I have added to my preseed file:
d-i preseed/early_command string cp /usr/share/backgrounds/mywallpaper-defaults.jpg /usr/share/backgrounds/warty-final-ubuntu.png
Even this one is never run:
d-i preseed/early_command string /usr/bin/touch /tmp/testearly
Thanks for helping !!