The Unix Heritage Society mailing list
 help / color / mirror / Atom feed
From: jnc@mercury.lcs.mit.edu (Noel Chiappa)
To: tuhs@minnie.tuhs.org
Cc: jnc@mercury.lcs.mit.edu
Subject: Re: [TUHS] Fwd: Choice of Unix for 11/03 and 11/23+ Systems
Date: Thu,  8 Oct 2020 19:49:57 -0400 (EDT)	[thread overview]
Message-ID: <20201008234957.16CED18C09E@mercury.lcs.mit.edu> (raw)

    > From: Paul Riley

    > Always darkest before the dawn.

Well, we'll see.


I found _that_ one; process 1 managed to exec() init, do a fork(), and then
the child process exec()'d the shell - then that apparently died, and the code
in init falls through into:

	termall();
	execl(init, minus, 0);

when the single-user shell exits, so then init restarted; rinse, repeat.

So a _lot_ of the code in mch.s seemed to be working correctly; system calls
(2 exec()'s, and a fork()) worked, processing switching worked, device
interrupts (for the disk and console tty) seemed to be working.. Not sure
what's left!

So I looked at mch.s again, to see what else _was_ there, and I noticed a
place where I used R0 as a temp - with the MFPS/MTPS thing to get to the PS,
instructions like:

      BIS	#340, PS

need to change to:

     MFPS	R0
     BIS	#340, R0
     MTPS	R0

and R0 was being used to hold an arg (in pword:), and was being bashed.


So I fixed it, and now the shell starts OK, but attempting to do any command
(e.g. "echo foo"), things hang (the shell doesn't fork). If I type the
interrupt character, the shell exits, and init restarts.

Oh well, hopefully this one won't be too painful to work out. The system's
mostly working, which I think will really help.

     Noel

             reply	other threads:[~2020-10-08 23:50 UTC|newest]

Thread overview: 70+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-08 23:49 Noel Chiappa [this message]
  -- strict thread matches above, loose matches on Subject: below --
2021-02-03  1:25 Noel Chiappa
2020-10-18 21:36 Norman Wilson
2020-10-12 22:43 Noel Chiappa
2020-10-12 19:27 Noel Chiappa
2020-10-10 23:29 Noel Chiappa
2020-10-11  2:30 ` Jay Logue
2020-10-11 23:24 ` Paul Riley
2020-10-12  0:53   ` Dave Horsfall
2020-10-12  1:56     ` Warner Losh
2020-10-12  2:09       ` Andrew Warkentin
2020-10-12 16:57       ` Arthur Krewat
2020-10-18 20:42     ` Michael Huff
2020-10-08 16:06 Noel Chiappa
2020-10-06 23:08 Noel Chiappa
2020-10-07  5:24 ` Jay Logue
2020-10-06 20:34 Noel Chiappa
2020-10-06 19:34 Noel Chiappa
2020-10-06 19:04 Noel Chiappa
2020-10-06 14:46 Noel Chiappa
2020-10-06 16:22 ` jay-tuhs9915
2020-10-02  0:39 Noel Chiappa
2020-10-01 12:51 Noel Chiappa
2020-10-02  0:23 ` Paul Riley
2020-09-30 23:16 Noel Chiappa
2020-09-30 18:51 Noel Chiappa
2020-09-30 17:58 Noel Chiappa
2020-09-28 23:21 Noel Chiappa
2020-09-30  1:50 ` Paul Riley
2020-09-27 21:07 Noel Chiappa
2020-09-27 21:12 ` Warner Losh
2020-09-28  0:22   ` Pete Turnbull
2020-09-27 20:50 Noel Chiappa
2020-09-29 13:20 ` Paul Riley
2020-09-25 22:08 Noel Chiappa
2020-09-26 14:52 ` John Foust
2020-09-28  0:03 ` Paul Riley
2020-09-28  0:06   ` Paul Riley
2020-09-24 18:56 Noel Chiappa
2020-09-24 13:04 Noel Chiappa
2020-09-24 18:24 ` John Cowan
2020-09-24 11:02 Paul Ruizendaal
2021-02-03  0:12 ` Greg A. Woods
2020-09-24  1:28 Noel Chiappa
2020-09-23 23:14 Noel Chiappa
2020-09-24  1:09 ` John Foust
2020-09-22 21:51 John Foust
2020-09-22 21:36 Noel Chiappa
2020-09-22 21:46 ` Warner Losh
2020-09-22 21:49 ` John Foust
2020-09-22 15:59 Noel Chiappa
2021-02-03  0:07 ` Greg A. Woods
2020-09-22  0:47 Noel Chiappa
2020-09-21 19:37 Noel Chiappa
2020-09-21 23:16 ` devin davison
2020-09-21 18:13 Noel Chiappa
2020-09-21 17:59 Noel Chiappa
2020-09-21 18:18 ` Arthur Krewat
2020-09-20 13:12 Noel Chiappa
2020-09-19 15:28 Noel Chiappa
2020-09-21 10:26 ` Paul Riley
2021-01-24 16:07 ` Tom Ivar Helbekkmo via TUHS
2021-01-25  4:58   ` Gregg Levine
2021-01-25  8:21     ` Tom Ivar Helbekkmo via TUHS
     [not found] <CAD05_j1bc6DDRtfPkd4QVeWXjwSp73bty46D=2ATozUbHThBWw@mail.gmail.com>
2020-09-19  3:22 ` Paul Riley
2020-09-19 14:20   ` Heinz Lycklama
2020-09-21 13:54     ` Paul Riley
2020-09-21 15:30       ` Heinz Lycklama
2020-09-21 23:27   ` Henry Bent
     [not found]     ` <4C35E6D2-8ABD-4DC2-BB2F-F15FA5BF30DD@icloud.com>
2020-09-22  0:22       ` Henry Bent

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20201008234957.16CED18C09E@mercury.lcs.mit.edu \
    --to=jnc@mercury.lcs.mit.edu \
    --cc=tuhs@minnie.tuhs.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).