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From: zik@yoyo.cc.monash.edu.au (Michael Saleeba [Zik])
Newsgroups: comp.os.mach,comp.sys.m68k
Subject: Mach m68k mailing list
Summary: FAQ on the Mach m68k mailing list
Keywords: list,m68k,mach
Message-ID: <1992Jun30.061140.7334@monu6.cc.monash.edu.au>
Date: 30 Jun 92 06:11:40 GMT
Sender: news@monu6.cc.monash.edu.au (Usenet system)
Organization: Monash University, Melb., Australia.
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The Mach m68k mailing list is a forum for discussion on a port of the
Mach 3.0 microkernel to the Motorola m68k series of processors. You
can join the mailing list by sending a request to:

machm68k-request@yoyo.cc.monash.edu.au

Currently volume on the mailing list is low. It is being used
primarily to gauge what features people want from the port and keep
them informed of progress.

Support will be provided for the following platforms (in roughly
chronological order):

* CPU
  - 68030      First code (for an Amiga 3000 since I have one)
  - 68020      Second effort (for an Amiga 2500 since I have one)
  - 68040      Well I have the data book but no 68040 :-(
  - 683xx      I know nothing about these devices but someone wants a port
  - 68010      Needs an MMU
  - 68070      Like a 68010 but with an MMU I gather. Could be a fun
               cheap UNIX alternative for existing Amiga/Atari users.

* FPU
  - 68881/68882            Default FPU
  - no kernel FP support   Smaller kernel if no FPU available
  - software 68881/68882 emulation   To run FPU software w/o FPU
  - 68040 FP emulation     To run 68881/68882 software w/040 FPU

* MMU
  - 68030 builtin    Most convenient platform
  - 68851            Basically for 68020
  - Sun3 MMU         Since it's basically free :)
  - 68040 builtin    Lowest common denominator. Defines page tables.
  - 683xx ?          I know nothing about these devices
  - 68070 builtin    Don't know much about this either.
  - 68451            Obsolete. Renowned to be truly ugly.

Is there anything important I have missed here? Support for
multiprocessing is going to be a pain, particularly considering I
don't have a multiprocessor to test it on.

I'm planning to use a common pmap system for the 040/030/851 devices.
The form of this implementation will necessarily be governed by the
lowest-common-denominator 040 MMUs.

As far as device drivers go, I'll be hacking up an interface to the
standard Amiga device drivers first. There are quite a few fairly
portable device drivers for SCSI and ethernet with the public Mach
distribution, so fortunately most people won't have too much pain
getting this ugly stuff done. Individual platforms are pretty much on
their own beyond this. I might provide a porting guide to save you
going through the same pain I'm going through right now with zero
documentation.

I'm not using the CMU Sun3 code directly. I am doing some things
slightly differently but I'm using their code as the definitive
reference. I also have incomplete 68030 code from Paul Mackerras which
should be handy. Thanks Paul! The OSF also donated 68030 core code
which I am looking at. Many thanks to Nawaf Bitar for this.

+-----------------------------------+--------------------------------+
|          -|-   Zik   -|-          | "She's not your satellite -    |
|     zik@bruce.cs.monash.edu.au    |  she doesn't miss you."        |
|          Michael Saleeba          |                       - TMBG   |
+-----------------------------------+--------------------------------+