That’s a good point about what the OS provides. I come from an embedded context, so often RTOS are not much more than a kernel that’s handling some basic threads and processor access. There was a really interesting talk at USENIX a few years ago (Usenix 21 keynote with Timothy Roscoe, I just looked it up) that was basically saying that a modern OS like linux, isn’t even accessing hardware and is just an OS in a system of OSs on a computer. So you are not wrong about what you are calling bare metal, but that usage is more popular at the moment, but the older meaning of bare metal actually just means “no OS.” It’s still very common in embedded world. They are the same words, but do have different meanings. I cannot find it at the moment, but about 10 years ago I had found a guy at Tufts (I think) who was publishing about actual bare metal (no os) single process machines that would run a server with nothing else. It was supposed to be helpful for security reasons. It was definitely whacky. I cannot find it because the server-farm usage of bare metal has taken over :( [Bare-Metal (redirect on wiki)[ en.wikipedia.org/wiki/Bare_metal ] I do now see that “bare metal server” is not going to be the right search term. Perhaps bare metal computing? I’m not sure. But what I am talking about pre-dates virtualization.

There was a really interesting talk at USENIX a few years ago (Usenix 21 keynote with Timothy Roscoe, I just looked it up) that was basically saying that a modern OS like linux, isn’t even accessing hardware and is just an OS in a system of OSs on a computer. This was indeed a very interesting talk. Not sure if the accusatory tone was warranted but I’m not really the target audience. One aspect that he only mentioned in passing is that hardware manufacturers seem to be very happy to entertain Linux’s (and Windows’) assumptions about memory, just like they seem to be very happy to entertain assumptions about execution order. Nobody wants to make hardware that requires a weird bespoke operating system because of its bespoke microarchitecture (except perhaps for Apple, though I’m not confident they’re really innovating in this regard). Maybe I lack perspective but I don’t really see a nice way out of this either, since nobody wants to buy hardware that requires weird bespoke operating systems either (except once again Apple). And I don’t see how an operating system could be widely supported across many different SoC designs without accumulating a similar complexity to modern Linux. We should definitely be feeling mildly uncomfortable about this entire thing though.

Looks like I’ve replied to you a few times, and sorry for the accusatory tone! Didn’t mean it! You did get me worried since I’m going to be used “bare metal” in my embedded class later this semester, and felt like I had gone insane not being able to find it anywhere. I was mostly just trying to convince myself this morning I wasn’t insane. I had thought it was the standard terminology. I do also need to caveat this that I am not familiar with whatever law OOP was referencing. I’m assuming it was one of the either baked-in surveillance or age verification things. Yeah, I’m with you and don’t really see a way out, unless we just step way back in time when we had less standardization and do bespoke everything. Cheers, and sorry for the tone!