From: lehmann@ans-netz.de (Oliver Lehmann)
Subject: [TUHS] Porting 2.11 BSD
Date: Wed, 25 Nov 2015 12:51:28 +0100 [thread overview]
Message-ID: <20151125125128.Horde.oGU9jlpPxZu6Cp9of9ENj6W@avocado.salatschuessel.net> (raw)
In-Reply-To: <CAH1jEzY2d-dVgjtLRKEQwTJcvAk000kAx7+T63QgMyfyKs0TbA@mail.gmail.com>
Hi Nick,
Nick Downing <downing.nick at gmail.com> wrote:
> According to this:
> https://archive.org/stream/bitsavers_zilogz80000mmu_742400/z8010_mmu_djvu.txt
> You could use only segment 0 and program the code MMU to point segment 0 to
> some physical address and the data and stack MMUs to point segment 0 to
> some other physical address and you have a split I/D system capable of
> running 2.11bsd assuming the compiler knows nothing of segments as you
> said. Or, as outlined in my previous posts you can use a compiler that has
> 23-bit pointers and understands how to output the high 7 bits as the
> segment and the low 16 bits as the logical address each time it
> dereferences a pointer (if such a compiler exists) and port 4.3bsd.
I have two compilers ;)
One compiler which creates "unsegmented binaries". The assembler code which
is generated only uses 16bit pointer addresses (r0-r15) and only works on
segment 0.
This compiler is for example used to compile the boot loaders and standalone
utilities iirc and other "small" binaries on my SYSIII.
http://pofo.de/cgi-bin/man.cgi?query=cc
There is also a "segmented compiler" which uses the 32bit registers (rr0-rr14)
to store the pointer adresses.
It is currently used for compiling the SYSIII kernel (which is much
bigger than
the 2.11 BSD kernel I saw) and all other "to big" binaries.
http://pofo.de/cgi-bin/man.cgi?query=scc
And this would mean that "such a compiler exists" (referencing to your
mail) and I could or should port 4.3 BSD?
next prev parent reply other threads:[~2015-11-25 11:51 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-21 13:00 Oliver Lehmann
2015-11-21 13:36 ` Jacob Goense
2015-11-21 14:03 ` Hellwig Geisse
2015-11-21 14:39 ` Clem Cole
2015-11-22 0:13 ` Random832
2015-11-22 0:27 ` Michael Kerpan
2015-11-22 2:04 ` Jonathan Gevaryahu
2015-11-22 0:30 ` William Pechter
2015-11-22 1:36 ` Oliver Lehmann
2015-11-22 2:13 ` William Pechter
2015-11-23 0:56 ` Nick Downing
2015-11-23 8:05 ` Oliver Lehmann
2015-11-23 8:40 ` Erik E. Fair
2015-11-25 0:09 ` Al Kossow
2015-11-25 10:14 ` Oliver Lehmann
2015-11-25 11:25 ` Nick Downing
2015-11-25 11:46 ` Nick Downing
2015-11-25 11:56 ` Oliver Lehmann
2015-11-25 12:10 ` Nick Downing
2015-11-25 11:51 ` Oliver Lehmann [this message]
2015-11-25 12:01 ` Nick Downing
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