This belongs on port-mac68k.

On Fri, 11 Feb 2000, Vasco Steinmetz wrote:

> launch the Booter automagically booting from dev sn0 type nfs?

AFAIK No, but you can recompile a kernel with

config              netbsd  root on ? type nfs

and it will do what you want--i've tested it.  You must, however, load
your kernel from a device accessible to MacOS.  This can be a floppy disk,
a hard disk, or an AppleShare volume.  Minimum boot volume is probably a
1.44MB System 7.5 Network Access Disk.

> Or is it possible to TFTP via BOOTP a kernel?

This could be added to the booter but isn't there right now.  I think you
could set up netatalk on your NFS server and load the kernel ovecr
AppleShare if you're up for a bit more work.  If you have other Mac's
around, it's useful work anyway.

> And why the heck is it not possible to boot directly from a floppy
> (would make a quiet system omitting a harddisk)???

It's possible to boot from a floppy, but I think it would be great to have
a SCSI tool that I could run from rc.local that would tell the disk to
spin down.  Maybe we already have one--anyone know?  Quietness is,
frustratingly, kind of a big deal in a lot of cases.


If your question is ``why isn't it possible to boot without MacOS,'' the
summary answer is:

 * No one has written the code yet.  Several have tried and either failed 
   or not finished yet.

 * It is difficult to write anything on mac68k because Apple is
   notoriously unhelpful in providing documentation, even now that they
   are parroting ``it's an Open Architecture!'' at every opportunity.
   This is why we don't have working sound or floppy disk drivers for
   _any_ Macintosh, and why the support for IOP-based Mac's is so shabby,
   as well as why the bootstrap intricacies are so poorly understood on
   mac68k.

 * Writing such a boot loader is IMHO a questionably valuable investment
   of developer time, since Apple's architecture is such that ROM's are
   ``patched'' by MacOS at boot time if bugs were discovered in them
   after the machine was released, and the Connectix Mode32 extension
   patches ROM routines that aren't 32-bit-addressing-aware on a few
   Mac's.  NetBSD calls the ROM sometimes, so ROM routines should be
   patched and 32-bit clean when NetBSD boots.  This is most easily
   accomplished by booting a recent copy of MacOS.

Others will disagree with me vociferously on the last point, because the
number of ROM routines that both get patched and get used by NetBSD is
supposedly very small.  Since I didn't write the code, their opinions are
probably worth more than mine.

-- 
Miles Nordin / v:+1 720 841-8308 fax:+1 530 579-8680
555 Bryant Street PMB 182 / Palo Alto, CA 94301-1700 / US