On Thu, 13 Jul 2000, gabriel rosenkoetter wrote:

> > What exactly is in the boot.fs? I assumed it had a kernel with a miniroot
> > in it. If this is so, who created it? Where did it come from? How do I get
> > a kernel that runs the miniroot install?
> 
> The floppy uses the GENERIC-MD kernel, as I recall, but you can't just
> write that kernel to a disk. That's why the boot.fs is supplied, it's
> written to a <GACK> file system, mounted from there (obviously) into
> an mfs one. All of this wrapped in a way that makes OF happy (it wants
> to see an HFS-like partition to boot files out of).
> 
> (<GACK> because I can't remember the name... vfs?)
> 
> PLEASE, someone correct me if I'm spouting wrong information here.

That's not quite it.

Apple has a way to have "drivers" boot a machine. These are special driver
partitions in the Apple partition map. When you boot off of "partiion 0",
the OF goes looking for one of these.

NetBSD supplies one of these (a program called bootxx) which reads a few
blocks off of disk, and thus loads ofwboot. ofwboot knows how to read ffs
file systems, and loads the kernel.

This technique works great on OF 1.0.5 and 2.0. It doesn't work on OF 2.4
or OF 3.X. We're doing something wrong with the driver partition so OF no
longer likes it.

The way the boot floppy works is that it has an ffs file system with the
GENERIC-MD (GENERIC with Memory Disk) kernel in it. So bootxx loads
ofwboot which loads the kernel. The kernel then boots NetBSD, and finds a
ram disk embedded into it.

> > Are there options that can be added to ofwboot.elf to tell the kernel to
> > prompt for the root device, like NetBSD-Amiga does? Is there documentation
> > for ofwboot.elf? loadbsd on Amiga has lots of options that get passed
> > along to the kernel.

I think -a works. Though actually -a makes both ofwboot ask where to find
the kernel and the kernel ask where to find root. It also used to be that
you had to type -a as an option at the line where ofwboot asked you where
to find the kernel - the initial "-a" had been forgotten. I think this
has been fixed.

> On Thu, Jul 13, 2000 at 01:23:02AM -0400, John Klos wrote:
> > What is this? Does this pertain to NetBSD 1.4.2? Is this why I can't do an
> > install with the 1.5-alpha ISO image?
> >
> > Did I just waste $1000 USD on a machine I can't run NetBSD on?
> >
> > Subject: Re: Any docs on NetBSD on B&W G3's?
> > From: Bill Studenmund <wrstuden@nas.nasa.gov>
> > Date: 02/07/2000 15:03:39
> >
> > One drawback is that OF puts the 646 pciide controller in a polling mode
> > our firmware initialization doesn't reset, so while you can boot from an
> > ide disk, you then can't use it.
>        
> As I recall, that means you can either boot from it *or* use it as 
> your root, but not both.

Exactly. However supposedly Manuel Bouyer recently fixed this problem. It
was that the 646 had two interrupt modes, compat and native. We didn't
support native, so if the firmware put the chip in it, we lost. But
someone should try it, it now might be fixed. Unfortunatly I don't still
have a G3. :-(

> (Thus all the talk of booting from CD-ROM.)

Or zip.

Take care,

Bill