So in the 90s I had different computer based classes in high school.
There was a "computers" class, which is probably the closest to what you're talking about, in which we mostly learned how to use Microsoft Works.
I also was fortunate enough to have some programming classes. We started out with QBasic and then the more advanced level was visual basic.
None of these discussed firmware. If it came up at all it was probably a casual side conversation because someone bricked something trying to update it.