Ask HN: How could we bootstrap our technology should everything get fried?

With Coronal Mass Ejections (CMEs) making the news, lots of us seeing the northern lights in lower latitudes, and some conversations about the layers of abstractions we in tech have built over the last century, I stumbled on a question that's bugged me for a while;

How will we bootstrap our tech once more should every electronic device get fried by a CME? How long will it take?

These days you "just" need a C compiler to get started and in theory you can build everything, but this assumes you already have a machine you can run something, it's already compiled, you have a monitor to output video to, you already have a text editor — even if it's just vi — and so on.

I am looking for something that starts from even lower, hardware included.

So I guess my question is, should everything be destroyed but we retain all the knowledge in books, how would we start rebuilding our tech?