I see postmarketos (based on Alpine, the most light-weight Linux distro) option for Ebook Readers :
https://wiki.postmarketos.org/wiki/D...Reader_Tablets
I got only one video on youtube:
https://www.youtube.com/watch?v=ByvmEqJvZBU
If anyone tried it or experimented it please do share your experience here. Is it really worth to change OS?
Alternative is
InkBox OS | (
forum thread) again based on Alpine Linux.