I have an old Kindle Fire HD device (running FireOS), which I do not use anymore.
Now I would like to test it for my mobile app development in regards to Android. I read about being able to run Android, instead of FireOS (which for sure is unsupported by Amazon).
However I wonder, whether it is possible to install something like a boot loader in order to be able to switch to different Android OS versions?
Yes, it is posible on certain devices using specialized kernel with multiboot feature, for example Siyah kernel for SGS3. I don't know anything about kernel with this feature for Kindle HD.
Maybe it's possible to run multiboot by modifying /etc/fstab...