15 Jul
2022
15 Jul
'22
5:15 p.m.
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.
- Matt G.
------- Original Message -------
On Friday, July 15th, 2022 at 1:51 AM, Paul Ruizendaal via TUHS <tuhs(a)tuhs.org>
wrote:
Message: 6
Date: Thu, 14 Jul 2022 17:51:39 +0000
From: segaloco segaloco(a)protonmail.com
Given V8 being rebased on 4(.1?)BSD, I suspect the path of least resistance would be to
just start grafting V8 code onto the working 4.1BSD.
I doubt that V8 is "rebased on 4(.1?)BSD": in my understanding it ported some
code from 4xBSD, but it is a different code base.
As I currently understand it, the V8 kernel:
- is a further development from 32V
- retains the code organisation of the V5..32V versions
- adds virtual memory code from BSD
- adds select() from BSD
and then adds all the V8 innovation on top of that (streams, file system switch, virtual
proc file system, networking, remote file system, support for the Blit terminal, etc.)
In particular in the area of networking the V8 kernel is organised quite differently from
the 4xBSD kernel, including the Chaosnet driver (i.e. it is streams based).
Paul 
15 Jul
15 Jul
5:50 p.m.
On Fri, Jul 15, 2022 at 11:15 AM segaloco via TUHS <tuhs(a)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
6:41 p.m.
Thanks for the insight, definitely a stronger case for 4.1BSD being involved in some way,
shape, or form. Here are a few SCCS strings from V8 vs 4BSD and 4.1(c)BSD.
init:
V8 - "(a)(#)init.c 4.3 (Berkeley) 10/13/80"
4BSD - "(a)(#)init.c 4.3 (Berkeley) 10/13/80"
4.1cBSD - "(a)(#)init.c 4.10 (Berkeley) 12/22/82"
getty:
V8 - "(a)(#)getty.c 4.1 (Berkeley) 10/1/80"
4BSD - "(a)(#)getty.c 4.1 (Berkeley) 10/1/80"
4.1cBSD - "(a)(#)getty.c 4.9 4.9 82/12/23"
Locore (not an SCCS string, but comment at top):
V8 - "Locore.c 4.11 81/05/15"
4BSD - "Locore.c 4.4 11/10/80"
4.1BSD - "Locore.c 4.11 81/05/15" (Note, used the BBN VAX version here, I
couldn't find the kernel sources in the 4.1cBSD on the archive...)
Main (kernel):
V8 - "main.c 4.14 81/04/23"
4BSD - "main.c 4.2 11/9/80"
4.1BSD - "main.c 4.14 81/04/23"
crt0: This one doesn't have SCCS info, is identical between V8 and 4BSD in ASM. The
crt0 in 4.1cBSD is in C instead, so not really comparable.
doprnt (c library):
V8 - "(a)(#)doprnt.s 4.3 (Berkeley) 3/22/81"
4BSD - No string...
4.1cBSD - "(a)(#)doprnt.s 4.4 (Berkeley) 11/25/81"
Granted, this isn't exhaustive by any means, but everything I've checked has
shown a much stronger 4 through 4.1cBSD character than V7/32V. It's too bad the
march from V7 to V8 isn't more documented, what I'm starting to see here is a
incremental approach where perhaps 4BSD was picked up, started to be modified into a
research version, and as useful developments were made at Berkeley, they continued to
merge in as well as make local changes until V8 was born.
This is all speculation on my part though, I don't want to establish history I
wasn't there for, but there is a strong case for V8 starting possibly as 4BSD with a
pretty open door to continuing to pull from BSD for a little while. Specifically,
I've seen more 4BSD alignment in userland, more 4.1BSD alignment in the kernel, but
it's all, as Dennis put it, "pretty eclectic".
- Matt G.
------- Original Message -------
On Friday, July 15th, 2022 at 10:50 AM, Warner Losh <imp(a)bsdimp.com> wrote:
On Fri, Jul 15, 2022 at 11:15 AM segaloco via TUHS <tuhs(a)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 
16 Jul
16 Jul
9:31 a.m.
On 15 Jul 2022, at 19:15, segaloco
<segaloco(a)protonmail.com> wrote:
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.
Not taken as combative - always working on the basis of my 'current understanding’
and that is evolving continuously as new views and facts present themselves.
My comments were intended around the kernel code, not the userland. That said, I’ve looked
into this a bit more and I think you were more right than I was.
"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
That is a good quote, but I think there is a better way to look at this, which is Warren’s
tool to establish similarity between files (it is integrated with the Unix Tree webpage on
TUHS).
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.
Looking at various kernel files in the V8 tree, it would seem that the most comparable
file in the TUHS database (and excluding V9-V10) would typically be “BBN-TCP”, closely
followed by “4BSD”. This BBN-TCP kernel code is based on a snapshot of BSD from August
1980 (see its history file). Joy sent it to Gurwitz for integration of the BBN TCP stack
with the BSD kernel. I think it is (or is close to) 4.1BSD.
From the output of Warren’s tool, it also seems that 4.1c deviated/evolved considerably
from that base. It would require a more in-depth comparison to say more, but based on this
quick check I think it is reasonable to say that V8 started from 4.1BSD (and not 32V as I
thought, or 4.1c as dmr remembered). It would be interesting to see what the
"enormous amounts scooped out” exactly were -- but maybe this refers more to the
userland than the kernel.
Some bits - like select() - were not in 4.1BSD and would have come from 4.1c. The V8
kernel still has a lowcore.s (next to lowcore.c). Interestingly, this has the best match
with later BSD versions. In all likelihood, there was cross-fertilisation after the
initial code fork.
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.
Yes, we have (now) reached the same conclusion, but don’t forget that V8 adds a lot of
innovation on top of that (streams, file system switch, virtual proc file system,
networking, remote file system, support for the Blit terminal, etc.). Networking in the V8
kernel (including Chaos) is organised very differently from 4.1cBSD.
Paul
10:31 a.m.
That sounds mostly right, from memory. V8 was definitely adapted from
some 4BSD, not 32V - there was major internal friction on that
decision. I will admit to being a defender of Reiser and London's VAX
port, which was screamingly fast. However.
Regarding select, I recall that Dennis implemented it and passed it to
Berkeley*, but maybe not. He certainly had a hand in its design; I
distinctly remember talking to him about it after one of his trips out
west.
-rob
A note for the historians: Bell Labs's Unix Support Group (USG), which
did development work for Unix, and was not even in the same building
as Research, was run by Berkley (sic) Tague. Thus we had Berkeley Unix
and Berkley's Unix and no end of fun and confusion on that score.
On Sat, Jul 16, 2022 at 7:32 PM Paul Ruizendaal <pnr(a)planet.nl> wrote:
On 15 Jul 2022, at 19:15, segaloco
<segaloco(a)protonmail.com> wrote:
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.
Not taken as combative - always working on the basis of my 'current understanding’
and that is evolving continuously as new views and facts present themselves.
My comments were intended around the kernel code, not the userland. That said, I’ve
looked into this a bit more and I think you were more right than I was.
"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
That is a good quote, but I think there is a better way to look at this, which is
Warren’s tool to establish similarity between files (it is integrated with the Unix Tree
webpage on TUHS).
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.
Looking at various kernel files in the V8 tree, it would seem that the most comparable
file in the TUHS database (and excluding V9-V10) would typically be “BBN-TCP”, closely
followed by “4BSD”. This BBN-TCP kernel code is based on a snapshot of BSD from August
1980 (see its history file). Joy sent it to Gurwitz for integration of the BBN TCP stack
with the BSD kernel. I think it is (or is close to) 4.1BSD.
From the output of Warren’s tool, it also seems that 4.1c deviated/evolved considerably
from that base. It would require a more in-depth comparison to say more, but based on this
quick check I think it is reasonable to say that V8 started from 4.1BSD (and not 32V as I
thought, or 4.1c as dmr remembered). It would be interesting to see what the
"enormous amounts scooped out” exactly were -- but maybe this refers more to the
userland than the kernel.
Some bits - like select() - were not in 4.1BSD and would have come from 4.1c. The V8
kernel still has a lowcore.s (next to lowcore.c). Interestingly, this has the best match
with later BSD versions. In all likelihood, there was cross-fertilisation after the
initial code fork.
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.
Yes, we have (now) reached the same conclusion, but don’t forget that V8 adds a lot of
innovation on top of that (streams, file system switch, virtual proc file system,
networking, remote file system, support for the Blit terminal, etc.). Networking in the V8
kernel (including Chaos) is organised very differently from 4.1cBSD.
Paul
659
days inactive
660
days old
4 comments
4 participants
participants (4)
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Paul Ruizendaal -
Rob Pike -
segaloco -
Warner Losh