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Date:Mon Feb 20 17:42:47 2001 
Subject:Re: sys_lock_system 
From:Aaron Sloman 
Volume-ID:1010220.01 

Stephen Isard <S.IsardDeleteThis@ed.ac.uk> writes:

> Date: Mon, 19 Feb 2001 13:31:04 +0000
> Organization: HCRC or CCS, University of Edinburgh
> ...

[AS]
> > In that case, I suspect that mkimage may be what you want.
>

[SI]
> Thanks, Aaron.  I'm afraid I'm thrashing about rather blindly.  A series
> of faulty conjectures

I often suffer from those...

> ... that I won't try to reconstruct led me to think I
> wanted to execute the code in $usepop/pop/src/syscomp/make_poplink.p by
> hand.
> ...
> > > ;;; MISHAP - sys_lock_system: CALLS OF writeable HAVE BEEN IGNORED
> > > ...
> > > no matter what I do.  In particular, if I start up poplog 15.53,

I did a few experiments and cannot replicate this mishap.

Maybe what you compiled before calling sys_lock_system autoloaded
some library that will not work with sys_lock_system.

On the other hand if mkimage successfully produces a saved image after
compiling the same stuff as you did prior to getting the mishap then
we'll really have a mystery.

[SI]
> I'm sure you are right that I didn't really want to be calling
> sys_lock_system at all, but someone might still want to have a look at
> that error message at some point, because whatever I was doing wrong, it
> was not failing to set pop_record_writeable to true.

I tried looking at the SYSPOP11 code for sys_lock_system in

    $popsrc/syslocksys.p

But it is pretty horribile, obviously interacting with some very low
level stuff that I did not understand.

If C is a high level assembly language then SYSPOP11 is a mixture of low
level assembly language and Pop-11.

See
    http://www.cs.bham.ac.uk/research/poplog/sysdoc/syspop11

(and other stuff in that directory).

It's easy to find the lines that produced your mishap message

	if _writeable_ignored _bitst (_flags _biset _:SLS_NONWRITEABLE_CLASS) then
		mishap(0, 'sys_lock_system: CALLS OF writeable HAVE BEEN IGNORED (pop_record_writeable not set true)')
	endif;

but I don't know if anyone but John Gibson can explain what's going
on there, and he has retired, alas.

Aaron
====
Aaron Sloman, ( http://www.cs.bham.ac.uk/~axs/ )
School of Computer Science, The University of Birmingham, B15 2TT, UK
EMAIL A.Sloman AT cs.bham.ac.uk   (ReadATas@please !)
PAPERS: http://www.cs.bham.ac.uk/research/cogaff/
FREE TOOLS: http://www.cs.bham.ac.uk/research/poplog/freepoplog.html