A filesystem, a shell, a program loader, and a hex editor! Well, maybe "editor" is overselling it. But from my point of view, it's as much an "OS" as MS-DOS was. MS-DOS also depended on the ROM BIOS.
I agree that it's probably not practically useful. But it's a brilliant hack!
Yes, BootOS very much in the same space as MS-DOS, although leaning even further on the "less-is-more" axis. It does the same basic things (though I suppose it doesn't do the BASIC thing).
Interestingly, there is modern OS in the same space. That's UEFI. Unti I played with it a few months ago, I thought it was some mysterious firmware-adjacent black-box. But actually it's just an OS, very similar to DOS (though it runs in protected mode).
It has a shell and some basic built-in commands including text editors and such. And most importantly it lets you run executables that a stored on a FAT (well, FAT32) filesystem.
The name BootOS could very well describe UEFI. And equally, a slightly more capable version of BootOS could serve as (very underpowered) UEFI replacement.
Yeah, PC-DOS was able to invoke the BASIC interpreter included in the IBM PC ROM, but MS-DOS had to rely on GW-BASIC loaded as a separate executable, which might or might not be present. BootOS is the same, except that its BASIC is only 512 bytes and somewhat more limited than GW-BASIC, but astoundingly it is documented to include a full arithmetic precedence parser with parentheses. No string variables or floating point, but still, unbelievable.
> I meant that UEFI doesn't have a BASIC interpreter (though probably someone has written one).
You wrote something else:
> Yes, BootOS very much in the same space as MS-DOS, although leaning even further on the "less-is-more" axis. It does the same basic things (though I suppose it doesn't do the BASIC thing).
I may be confused here, but I don't think UEFI includes a shell — although there's a shell called UEFI-Shell which you can install on your hard disk and run under UEFI — and I think UEFI doesn't have any way to enter machine code from the keyboard. In fact, I think even UEFI-Shell doesn't have any way to enter machine code from the keyboard; is that true? Also, am I mistaken about the status of UEFI-Shell?
So, although I am not planning to switch my laptop to running BootOS, I think there are some significant things BootOS can do that UEFI can't.
I agree that it's probably not practically useful. But it's a brilliant hack!