On Thu, Sep 25, 2003 at 09:59:29PM -0500, Zach Lowry wrote:
> I got to thinking the other day about writing support for NuBus PPC
> machines. Since we're in need of a bootloader, what about using the
> mac68k booter app? Would major changes need to be made? It seems to
> be a better choice than using BootX, since it already understands UFS
> and etc, plus we have the formatter and installer utilities. 

It's a neat idea, but there are a lot of changes that would have to be
made.  It wouldn't really save any time on the BSD side, and large parts
would have to be rewritten on the Mac side.  The boot process itself
would have to be entirely different, and there would have to be some way
to get into supervisor mode (not an issue on MacOS/m68k).

With BootX, I think we'd be looking at a multi-stage boot, not too
unlike what we do now on a number of platforms, including OF-based
PPC.  We'd point BootX at the beginning of a partition, teach it how
to load a few blocks of code to a known location, make sure caches
are flushed, and jump into the loaded code.  That code would understand
the UFS/FFS/LFS/RAIDframe/whatever, and really be the equivalent of
ofwboot.{xcf,elf}.

Pax,
-allen

-- 
 Allen Briggs                     briggs@wasabisystems.com
 Wasabi Systems, Inc.             http://www.wasabisystems.com/