On: How modern Linux systems boot

[predakanga]

If you're interested in the userspace machinations, as opposed to what goes on in the kernel, there's a great rundown on this StackOverflow answer: https://unix.stackexchange.com/questions/226872/how-to-shrin...

There's also https://github.com/marcan/takeover.sh (previously on HN: https://news.ycombinator.com/item?id=13622301)

Both of these share a similar premise - set up and transfer control to an in-memory root filesystem, in order to make major changes to the real root filesystem.