Voila la solution
The easiest way to fix this problem is as follows:
download
http://dreamboxupdate.com/opendreambox/2.2/stable/images/dm820/vmlinuz-rescue--3.4-r0.3-dm820-20160405.bin and save in your downloads folder.
You need a TFTP server on your notebook or PC. For Windows, this one is easy to use:
http://www.heise.de/download/product/pumpkin-tftp-serverclient-19325/download/danke?id=19325-1You may have to set up your firewall to allow "Pumpkin" to access your network, in case of doubt, deactivate the firewall completly for this stip.
The box has to be connected by ethernet cable to your local network, preferrably with a DHCP server. Should it be necessary, it also works without DHCP server, explanation is down below.
In addition, you will need a terminal emulation program, for example putty. But since you already see the debug output of the box, you seem to already have such a tool.
In the Pumpkin TFTP server you need to configure the shared folder that contains the vmlinuz.....20160405.bin file.
In the terminal program you need to enter the following command at the CFE> prompt:
boot -tftp -elf PC-IP:vmlinuz-rescue--3.4-r0.3-dm820-20160405.bin
You need to replace PC-IP with the IP address of the machine that you're running the TFTP server on.
If you see the graphical menu of the bootloader instead of the CFE> prompt, press Ctrl+C.
If you don't have a DHCP server, you need to give a static IP to the box first. You can do this with: ifconfig eth0 -addr Box-IP where Box-IP is an IP address out of the same range as your PC,
e.g. if your PC has 192.168.178.10 then give the box IP 192.168.178.30 or something like that.
ifconfig eth0 -addr 192.168.178.30
Then retry the boot -tftp.... command.
If it worked, the box will automatically boot the usual rescue loader menu, which allows you to flash the normal way using your browser.
But since the rescure loader is just executed from RAM after loading it via TFTP, you also need to flash the rescue loader after flashing the normal boot image.
You can do this with the rescue loader or after booting up the normal linux system.
For this you need to connect via telnet/ssh or the login prompt on the terminal and run
cd /tmp
wget
http://dreamboxupdate.com/opendreambox/2.2/stable/images/dm820/vmlinuz-rescue--3.4-r0.3-dm820-20160405.binflash-rescue /tmp/vmlinuz-rescue--3.4-r0.3-dm820-20160405.bin
After this, the rescue loader is restored.
