Raspberry Pi - Stuck in boot after installing upstart

I  installed upstart so I could run a script at startup [native /etc/init/*.conf]  with [sudo apt-get install upstart] and I then rebooted my RPi. Afterwards my RPi running Debian-Jessie was pretty much unresponsive via the network. Right after connecting it to my monitor I then realised that it was stuck on boot.


[   17.777252] init: samba-ad-dc main process (513) terminated with status 1
[  133.770712] init: failsafe main process (364_ killed by TERM signal
[info] Using makefile-style concurrent boot in runlevel S
[info] Loading kernel module fuse.

Only at that moment, I started realising that I should have probably backed up my SD Card before, but then it was already too late. It then struck me - Does this mean I will have to redo it all over again with a new and fresh raspbian installation. That was definitely not something I was looking forward to do, especially not after I have invested my time to this project, the amount of packages and dependencies I have installed. Reflashing was not an option.

And then it hit me, A while ago - I had more or less the same issue on my Xubuntu 12.04 install and managed to get away with it via chroot which then worked, that is when I started researching, if it is possible to chroot my ARM Raspbian install from an Xubuntu system. To my revelation it was...And below is a recipe I followed which helped me to rollback to Systemd-sysv without having to burn a new Raspbian image to my SD card.

First, install two packages on your Ubuntu system: qemu-user, and proot.

sudo apt-get install -y qemu-user proot

After you mount the Raspbian SD card, you can do the equivalent of a 'chroot' with:

sudo proot -q qemu-arm -r /mnt/raspbian_sd_card

I was then able to chroot/proot to my raspbian install and removed upstart:

sudo apt-get -y purge --auto-remove upstart
This command will also automatically re-install systemd-sysv