Subject: Re: Native boot [was Booter 1.8]
To: Allen Briggs <briggs@puma.bevd.blacksburg.va.us>
From: Bill Studenmund <wrstuden@loki.stanford.edu>
List: port-mac68k
Date: 12/15/1995 10:51:56
>
> > IMHO it is more important to get NetBSD/mac68k to boot _native_ without
> > requiring a MacOS license, or 'Booter'.
What do you mean by "native?" I see an advantage to skipping the MacOS
boot time, but isn't MacOS the native operating system (the one the
ROMs are built to support)? Also, why do we need a MacOS licence? The
only computers our port runs on came w/ Apple ROMs and a version of MacOS?
> This would be nice, but the main hurdles that have to be cleared are:
> - dealing with 32-bit/24-bit/memory map issues
> I don't know how bad this might be
> - dealing with re-locating the boot program so the
> kernel can be loaded at address 0
> - dealing with various disk formats/machine configurations
> - getting the information that booter now passes to the kernel
>From what I'm learning about the variability of hardware configurations,
we'd be duplicating a lot of work the MacOS does now. Without
documentation. Problems like the apparent power control stuff on
the PowerBooks might be quite nasty.
> > How could this work for a hard-disk where the ROMs expect to
> > load a device driver from the disk? The ROMs obviously have
> > to be able to read blocks from the disk, so wouldn't the
> > bootblock just use this feature to read the second-level boot,
>
> I need to look over the docs again, but I'm not sure that this is a
> problem. If it is, we can certainly work with it, providing a minimal
> partition map with a driver partition. I am willing to cede that much
> to the Mac ROMs... ;-)
>
> > Would the MRG code still work? (considering no ROM patching
> > done by MacOS)
>
> That's an issue now. The ROM patches from the MacOS aren't loaded into
> NetBSD. (One of my arguments against using something like MRG in the
> first place.)
>
> > What would it take to have NetBSD/mac68k support "native"
> > disklabels, which would be required for standalone?
>
> Some sweat. That's about it.
Maybe we could just steal the Sun port's partitioning stuff? A few months
ago I started a long thread on current-users about being able to read
other ports' disklabels. Everyone hashed out a lot of problems, and
then nothing got done. Maybe this would be a time to start on that road,
seeing as we'll need to be able to read "native" (NetBSD-modifiable)
and MacOS-based disklabels.
> > The real question, I guess, is: Does anyone other than me want this
> > functionality? I personally don't use the IIci for any "Mac" type stuff,
> > so having the ability to use MacOS isn't necessary for me.
>
> I'd like to see it. It's just not a priority for me. ;-)
I don't really care about booting w/o MacOS, but I agree it would be nice
to boot to NetBSD quicker than presently. One intermediate solution might
be to work to squeeze everything onto a floopy. Doesn't System 7 still
respect the "first-launch" parameter of the boot block even though the
Finder is a special program for the OS? If we made a boot floppy w/
just the system file and Booter, couldn't we get the system to run Booter
automatically?
Take care,
Bill