When you have the possibility to use a serial console (TTL/MAX232): https://www.cyrius.com/debian/kirkwood/qnap/ts-219/serial/
You can use this steps to recover stretch: https://www.cyrius.com/debian/kirkwood/qnap/ts-219/uboot/ for that you have to setup a tftp-server and you need to use the following images: initrd: http://ftp.debian.org/debian/dists/stretch/main/installer-armel/current/images/kirkwood/network-console/qnap/ts-21x/ kernel: http://ftp.debian.org/debian/dists/stretch/main/installer-armel/current/images/kirkwood/network-console/qnap/ts-21x/kernel-6282 (TS-212P) that’s it. greetings -----Ursprüngliche Nachricht----- Von: Patrick Leibach [mailto:tigerleib...@web.de] Gesendet: Dienstag, 20. August 2019 20:13 An: t...@cyrius.com Cc: debian-arm@lists.debian.org Betreff: Flash Question: Debian on QNAP Hey Martin, I have a QNAP TS-212 and successfully flashed Debian to the md3 and md5 to install Debian. I've been using it now, since a while and also upgraded to Buster. Now I'd like to fall back on Stretch while installing everything from the scratch. I tried to follow your instructions on http://www.cyrius.com/debian/kirkwood/qnap/ts-219/install/ but unfortunately the shell scricpt only works in QNAP firmware. How can I change the script, that it works from Debian or How can I manually flash the initd and kernel to the flashblock3 and 5 Thanks for your help Patrick