[TUHS] Re: Question about BSD disklabel history

[Dan Cross <crossd@gmail.com>]

On Sun, Dec 31, 2023 at 6:25 PM Larry McVoy <lm@mcvoy.com> wrote:
>[snip]
> OpenFirmware is Mitch Bradley's baby.  I believe it ran on 68k Suns,
> there was some sort of boot prom there.  I mostly used it on SPARC.
> It was pretty powerful but my personal feeling is the choice of
> Forth didn't help.  Yeah, I get it, Forth is like some weird lisp
> and the lisp people love lisp.  What the lisp people don't get is
> there are a lot more people who don't love lisp than do love lisp.
> And trying to get everyone to love lisp isn't gonna happen.
>
> That said, what else could Mitch have used at the time?  Tcl?
> Please, another weird lisp.  Perl?  Not really something that
> wants to talk to the bare metal.
>
> It's a serious question, is there anything that Mitch could have
> used that would have had wider appeal?

The thing about FORTH isn't that it's Lisp-like (as Alec mentioned),
though its supporters do often exhibit a fervor reminiscent of
Lispers.

Rather, I think FORTH shows up in places like this because it's
possible to write _incredibly_ lean threaded-code interpreters for it
that can run in really primitive environments, so you can shove a
really small interpreter in a ROM and keep your big CPU in reset while
you run it out of a tiny SRAM on an 8-bit microcontroller or something
until you've got enough of an environment going to train DRAM and
transfer over to the real thing. E.g., something like:
https://pygmy.utoh.org/3ins4th.html

What could you have done differently? Meh; I don't really know, but see below.

> And I agree whole heartedly with the EFI crap being a giant step
> backwards.

Ironically, the UEFI people have done something _similar_ to OF in the
form of AML (ACPI Machine Language), which is a byte-code
serialization ASL (ACPI Source Language); presumably that's system
independent. The idea of a p-code representation is about where the
similarity ends, though: AML exposes a mechanism to talk to the UEFI
OS for a whole slew of stuff, which is rather unlike what OF did
(though I again have a vague memory that on SPARCstations some devices
went through the PROM monitor; the text console, for example, and
maybe the keyboard? It's been too long now to properly remember).

Anyway, an alternative to FORTH might have been a well-defined p-code
and a little VM in ROM to drive it.  Then one could compile to that
using whatever language one liked (and was willing to write a compiler
for!). Perhaps the feeling is that that is what FORTH was; for that I
guess I don't see any reason one couldn't transpile to FORTH from some
other language.

        - Dan C.