Default flash linux on ARM tablet, for fastest boot?

hello forum. so my situation is this :
i have a tablet, on my car, which i use as a speedometer. it runs a program i have writen on java. the problem is, i dont like to have the tablet stay on sleep. i would prefer if the tablet was turned off, and turned on only when i wanted...

so i wanted to flash the tablet (ARM cortex8 cpu), with a linux distribution, that would boot fast. i dont want the distro to have anything special. just to be able to run java programs, have compatibility for the touchscreen, and also be able to initialize, USB comunication (Serial)...

the probelm is, i cant seem to find any reliable source, on where to begin.... so, could someone point me on some direction ? thnx!