[TUHS] Re: V8 4BSD or 32V Based? (was: Unix V8 Chaosnet, any takers?)

[Warner Losh <imp@bsdimp.com>]

[-- Attachment #1: Type: text/plain, Size: 2226 bytes --]

On Fri, Jul 15, 2022 at 11:15 AM segaloco via TUHS <tuhs@tuhs.org> wrote:

> Re-subject'd as this part of the conversation diverges.
>
> Found the quote that I was thinking of when I said that:
>
> https://yarchive.net/comp/bsd.html
>
> "Research Unix 8th Edition started from (I think) BSD 4.1c, but with
> enormous amounts scooped out and replaced by our own stuff." - Dennis
> Ritchie
>
> The "I think" adds some murkiness for sure.  There's definitely a good
> chunk of code from 4BSD.  Compare init, getty, locore.c (as opposed to .s
> in V7 back).  Heck, even the main.c between the two kernels are more
> similar to each other than V7.  I would almost opt towards calling that
> being rebased on 4BSD rather than V7 with bits and pieces of BSD added.  I
> could see it being more beneficial to start with 4BSD and tack on necessary
> Bell bits rather than take V7/32V and try and shoehorn in the VM
> implementation for VAX.
>
> The 4.1cBSD copy on the archive does appear to be pretty different, so in
> terms of raw comparison, I suspect the basis is 4BSD rather than 4.1cBSD.
> I don't know that we have a clean copy of 4.1BSD gold, I'd be interested to
> see if the structure of the source code changed between 4.1 and 4.1c, as
> 4.1c does exhibit the new organization by the BSD folks, 4BSD still shows
> folders like cmd, lib, and so on.
>
> Not trying to be combative by any means, but I've been doing a bit of
> research lately into when V8 was snapped from BSD and where Bell and
> Berkeley then diverged from that last major confluence, especially with a
> focus on init and other early stages of userland.
>

The biggest differences between BSD4.1 and BSD4.1c were the addition of FFS
in 4.1b (we have 4.1a from Kirk's DVD, as well as 4.1 and two versions of
4.1c). There's no ufs that I can detect in V8 though.

If we look at the vm, the 4.1c.2 files are from 83, the 4.1 files are from
80 and the v8 files are from 81.

Kirk's DVD has a 4.1.snap on it that lines up more closely with at least
the vm files. I don't recall what these files are from. It's not present in
the TUHS archives that I see. This snapshot is about a year after 4.1BSD
release, but maybe 18 months before the 4.1a snapshot.

Warner

[-- Attachment #2: Type: text/html, Size: 2778 bytes --]