Subject: Re: multi-boot sparc CD
To: Robert Elz <kre@munnari.OZ.AU>
From: Kurt J. Lidl <lidl@pix.net>
List: port-sparc
Date: 03/16/2000 14:42:58
On Fri, Mar 17, 2000 at 03:15:30AM +1100, Robert Elz wrote:
> I have no idea whether anyone has done this before, but just in case
> it hasn't been done, I thought I'd report that it works.

I haven't done this with NetBSD, but I've certainly done it with
BSD/OS (sparc) dozens and dozens of times.  There are some relevant
details to share.

> That is, I have it so that the default boot on a sun4 is the boot142.fs
> (install script) version, and the default boot on a sun4c or sun4m os
> syboot142.fs.   Then by using "boot cdrom:b" or "boot cdrom:c" (or :d)
> either of those can be selected from the prom.

Actually, a "more correct" way to do this is as follows:

Put the sun4c boot area on cdrom:c
Put the sun4m boot area on cdrom:d
Put the sun4u boot area on cdrom:f

If you look at the devalias entry for "cdrom" on a sun4m, you will see that
it is actually something like this:

cdrom=/iommu/sbus/espdma@f,400000/esp@f,800000/sd@6,0:d

And on an ultrasparc, it looks like this:

cdrom=/sbus/SUNW,fas@e,8800000/sd@6,0:f

For BSD/OS, the sun4c and sun4m boot areas are the same, since they
use the same bootstrap code.  Just make sure that your sun disklabel
has the same starting and ending offsets for the sun4c/sun4m
partitions and you won't have any problems.  The ultrasparc support
uses a different bootblock and a different /boot program.

> It is more than kind of nice that Sun CDs need different images for the
> different hardware types, and NetBSD doesn't...

I don't follow you on this -- Solaris 2.6 has a single large ISO
filesystem that all artchitectures use, and just have custom bootblocks
in the c: d: and f: partitions (as noted above), which direct the
boot loader program which base kernel to load out of the ISO filesystem.

-Kurt