As I got great help from this forum with my project I would like to publish my notes on it here.
This is not a real howto or tutorial, just briefly some hints for people trying to achieve the same as I. There certainly are several typing mistakes in it - sorry.
Get Tinycore linux version for RasPi2 (Picore) wit X (I used Vers. 6.1 final)
put the image file on a SD-Card
dd if=path/to/image.img of=/dev/sddOrWhateverTheSdOnYourSystemIs
use Gpartred to enlarge the second partition on the SD Card
Boot PiCore on Pi
Prepare:
use the Install Apps Tool to install (onBoot)
nano
midori
wifi
Fullscreen
to get rid of the black borders on the screen:
use mount tool to mount Partition 0
use nano to configure the config.txt there and remoce the # from the line "disableOversacn=1"
Wifi
use the Icon on the desktop to connect to prefered wifi
check the file /home/tc/wifi.db (path my be wrong) that the first line is you prefered Network SSID an Password
use nano to edit /opt/bootlocal.sh an add this line so the Pi autoconnects to the first networ listed in the wifi.db file. Add:
/usr/local/bin/wifi.sh -a 2>&1 > /tmp/wifi.log (not 100% sure here)
Screensaver off
To disable screen blanking and any screensavers I added
"xset s off -dpms"
to /opt/bootlocal.sh
and (to be save) as well to
/home/tc/.X.d/xaus.sh
Launch Browser
Midori is the only availabel browswer (yet?)
it is tempting to create a file like
/home/tc/.X.d/midori.sh
with a content like this
midori -e Fullscreen -a
http://www.pageYouWish.debut that does not work, it it necessary to set midori in it's settings menu to start with
http://www.pageyouwish.de/ as homepage and then create the file
/home/tc/.X.d/midori.sh
with this content
sleep 50
midori -e Fullscreen
the sleep 50 gives the wifi 50 sec to connect after startup then use the settings menu or the reboot dialogue to backup all your changes and that should be it:
after plugging in Pi it will boot, connect to wifi an display the set web page. It can be unplugged without the file-system to be corrupted.