Amiga GigaPD 3/Amiga_GigaPD_v3_3of3.iso/netbsd/readme.first

Text File | 1993-06-25 | 9KB | 204 lines

******************************************************************************

Here's the initial version of NetBSD for the Amiga. This version is strictly
for the kernel hackers among you, there's no sense in `normal' users trying
to install it, possibly killing their other partitions, facing kernel panics and
not knowing what to do. Please keep that in mind, if you feel like going on...

******************************************************************************


Currently supported equipment:
-----------------------------

o any Amiga with either 68020/68851 or 68030, 6888[12] is currently required
  (because fpu code is conditionally compilable in the kernel, and this
   version contains fpu code).
o A3000 internal SCSI controller. Note that you cannot boot BSD currently
  with any other SCSI controller (not to mention weird IDE interfaces..).
o internal RS232 port. This is not by default used as the system console.
  you have to recompile if you want the console on the RS232.
o some `sort of' VT200 emulator for the custom chips display, which is
  an NTSC laced, 640x400 monochrome display. This is the default console.
o disk and tape drivers using the mentioned A3000 scsi controller.
  Disks I tried it on include: Wren7, IBM-OEM 0663E12, Quantum LP105S.
  Only tape tested is my Wangtek 5150ES.


Some comments on these:
----------------------
68020&68851/68030 support:
    These cpu's should be fully supported. Note that you cannot run
    BSD with a '30EC, the MMU is absolutely required. The '40 is
    currently *NOT* supported, don't try! The reason for this is
    the braindamaged, mind boggingly stupid '40 MMU, which only
    implements a very limited subset of the 68851/68030 MMUs. In
    particular, it doesn't deal with the current 2-level MMU
    setup. See the extra doc about AMIGA-MMU for details.
    Exception handling for the '40 is also different to its predecessors,
    however this should be easier to implement than revamping
    the MMU code to work on the '40.

A3000 internal SCSI controller:
    This is a driver tested on an AMD33C93A chip, I just hope I
    didn't do anything that won't run on the dreadful WD33C93A-PROTO
    still in use in thousands of A3000. It is a *VERY* rough
    driver, it's really a hack, and should be replaced by a chip-
    specific low-level driver for use with the generic scsi/*
    code for the PC. Might even use Mach-drivers as well. The
    driver would support DMA, if only DMA would work... That is,
    DMA trashed my memory, so I disabled it for a while, and the
    driver was degraded to a PIO in the meanwhile.. Hope to get
    DMA up again RSN ...
    Note that (contrary to Amiga Unix..) this driver should handle
    drives ok that send sync-requests (it just rejects those..).

Internal RS232 port:
    Well, that's not exactly a terribly complicated thing.. It should
    perform reasonably well, but I didn't really test it with file
    transfers, just with my old VT100. It should do hardware flow-
    control, but that's not tested either. The driver supports being
    a console.

Custom chips display, console:
    I implemented the console in a two-layer approach stolen from
    the hp300 implementation. There is a low-level layer (grf*)
    responsible for creating a display (`view' in AmigaOS parlance),
    and a hi-level layer (ite*) dealing with display of characters,
    scrolling regions, handling keyboard, etc. This approach should
    it make trivial to support consoles on custom graphics boards.
    Grf currently opens an interlaced NTSC screen, with a resolution
    of 1024x1024 pixels, and a visible display size of 640x400. It
    provides for smooth scrolling of this display window inside the
    larger bitmap (once the ioctl's are implemented..), and it can
    handle overscan (by changing the visible display size and moving
    the display offset). These ioctl's aren't implemented yet either.
    Oh: don't try to convince me to offer a PAL display, I won't.
    The console tries to be some sort of VT200 compatible terminal,
    however, I only implemented a small subset of features. Essentially,
    I took the existing HP-ite driver, a VT320 manual, and started
    to replace the control sequences with the ones I found in the
    manual. Don't expect the driver to do downloadable fonts or other
    weird features, I think even scrolling regions might be broken
    at the moment. It should however work reasonably well for most
    editing purposes.


Keyboard:
    Default keymap is US-ASCII. However, I reasoned quite a bit about
    how to do the mapping of keys into characters and character
    sequences to easily change the keymap to international layouts.
    Dead-keys are supported, as well as having a second set of keys
    reachable with the Alt keys (same usage as AmigaOS). Thus, you
    should be able to generate an ÷ (oe) by typing Alt-k o.
    However, currently any 8bit characters just appear as ^@ on the
    screen, and I don't know whether the tty is responsible for this
    misfeature, or whether I have a bug in my alt-key handling...
    All keys sending <CSI> sequences send <CSI> as <ESC>[ instead of
    \x9b, as under AmigaOS. This should make use with Emacs, Bash, etc.
    *much* easier.
    For information about how keymaps work, look at dev/kbdmap.h and
    dev/kbdmap.c.

Disks:
    See the special section on how RDBs map into BSD partitions.

Tapes:
    The tape driver seems to support a variety of different tape
    drives. Chances are, your tape will work too. Just give it a try,
    worst thing that can happen is a kernel panic ;-)



RDB's and how BSD finds its partitions on disk drives
-----------------------------------------------------
BSD partition tables usually look like this:
    A:    boot partition, ~8M
    B:    swap partition, twice the (Fast)RAM size you have
    C:    the entire disk
    D:    /usr
    E, F, G, H:    additional partitions

Since Amiga partitions are managed thru a RigidDiskBlock (RDB) stored
in the first cylinder(s) of a drive, I took the following approach to
map Amiga partitions to BSD A-H partitions:

C:    still is the entire disk. Take extreme care!!
A:    has identifier:    BSDR    (Root fs)
B:    has identifier: BSDS    (Swap fs)
DEFGH:    have identifiers: BSDD, BSDE, BSDF, BSDG, BSDH.

BSD recognizes at most one partition of each type per drive, but you can
have multiple BSDD partitions on different drives, for example.

There is no restriction on the volume name for those partitions, and
there's no restriction on the order of the partitions on the disk, you can
have BSDD before BSDR, for example.

-> IMPORTANT NOTE: BSD will boot off the last BSDR partition it finds,
                   ie. if you have a BSDR partition on drives 0 and 6,
                   it will boot from the one in drive 6 !!

I'm running BSD on my Amiga with BSDR, BSDS, BSDE on drive 6, and a
BSDD on drive 1. BSDD on drive 6 is a backup root filesystem, I can just
change its type to BSDR, change the BSDR type to BSDD (ie. swap them), and
boot off the other partition, without BSD noticing anything.


Using UFS partitions formatted under Amiga Unix System V Release 4
------------------------------------------------------------------
You can use such partitions under NetBSD-Amiga, however, you cannot use
partitions formatted (newfs/mkfs) under NetBSD-Amiga under Amix. Amix
uses the old BSD-4.2 ffs, and doesn't understand the new BSD-4.3 ffs.


Other documents
---------------
The BSD distribution contains a huge doc directory, so if you want to
know everything about XYZ, chances are you'll find a manual for it there.
The other short docs in this distribution cover:

 AMIGA-MMU:    short description of what's going on when initializing
         the system.

 BUGS:        you might guess what this contains :-)

 INSTALL:    quick guide on how to install the included dump of the
         root filesystem on your harddisk. This is quite risky,
         please read the warnings, and only try the installation
         if you feel totally confident that you understood the
         process!

 README.first:    this file.

 RECOMPILE:    short notes about how to change the default configuration
        (throw out unneeded drivers, add drivers for other
        SCSI units, etc). Recompiling probably requires a lot
        of experience in this sort of things (possibly from already
        hacking around with the Mach kernel...), I'd imagine
        make'ing the kernel requires a lot of unix'ish tools
        not commonly found on `normal' amigas, however you
        should find most of them in the Mach distribution.


Distribution of NetBSD-Amiga
----------------------------
I'll try to put my updates on ftp.eunet.ch, given that I don't run out
of diskspace there. After integrating the Amiga changes into the official
NetBSD sources, you'll also be able to get the (entire) distribution
from sun-lamp.cs.berkeley.edu, or any of its mirrors. I'm using the
NetBSD-current sources, and am updating my source tree regularly, however I
didn't incorporate the most recent changes before the first release, since
I've worked with this version for some time now, and found it to be
fairly stable (so no loadable kernel modules yet in this release).

There is going to be a mailing-list for NetBSD-Amiga, I'll post the
information to comp.unix.amiga when I know its definite name and location.

You can reach me at [e-mail], please mention `BSD' in your Subject:
line, this makes it easier for me to automatically sort incoming mail
according to topic, thanks!

-Markus Wild