WEBTOP - How do Ubuntu and Andriod get along?

Question

linux

Has anyone figured it out on their own, or maybe where they met an explanatory description of how Ubuntu and Andriod coexist on Motorola devices? On the one hand, there is only one kernel, Linux. On the other hand, judging by the videos on YouTube, after connecting the same Atrix to the dock, it takes only a couple of seconds before switching to webtop mode. How does the shell start so quickly and the missing components are loaded? And after shutdown-ubunta dies or falls asleep? And why does the phone run on battery for such a long time?
Does anyone know of similar developments or attempts to repeat such tricks on homemade firmware for other devices (except Ubuntu for Android)?

Answer 1

I can't tell you all the details (NDA, all cases). The first time when connecting, it starts a little longer, because the x's start. After disconnecting from the dock, the freibuffer with X just hides and that's it. Ubuntu has been living in the background for some time. Accordingly, when connected back, the framebuffer with X's is again displayed on an external monitor.
It lives for so long, because for the processor there is practically no difference what is running there - an android, or an android paired with x (until, of course, some resource-intensive application starts). The main battery consumption of the dock, as you might guess, goes to power the backlight of the external screen.
The processor itself is pretty energy efficient.

Answer 2

By the way, I also could not find any sensible information on this topic (