.py = python
check AVM FRITZ!Box 7412 stuck in ramboot - #3 by nicefile
you do.
it's done by scp:ing the sysupgrade image to the routers /tmp folder, then running sysupgrade /tmp/sysupgrade.img.name
, while ssh:ed to the initramfs.
did you find any info about it being flashable via TFTP ?