Subject: Re: mfs root without using kernel's memory disk storage area?
To: None <netbsd-help@netbsd.org>
From: Laine Stump <lainestump@rcn.com>
List: netbsd-help
Date: 03/08/2002 11:38:52
Luke Mewburn <lukem@wasabisystems.com> writes:

> The 2.88MB limitation is not a limit on the size of the memory disk,
> it's a limit on the size of "floppy" file system image that the BIOS
> can boot from the CD.  For NetBSD installation CD-ROMs, that contains
> the "INSTALL" kernel which has a 2MB root file system stuffed into it,
> and the result is gzip -9-ed. 
> 
> One possibly solution is to implement a "/boot" which is installed in
> the 2.88MB "boot image" on the CD-ROM, and that "/boot" knows how to
> find a NetBSD kernel on the ISO file system.  That NetBSD kernel can be
> as big as you like (within reason, up to 32MB ?), and you can stuff
> the memory disk into the tail end of that.

And as long as you're going to do that, you might as well take
advantage of the fact that you no longer need the kernel in the boot
image, and use a 1.44MB boot image rather than 2.88. This would allow
the CD to boot on systems which don't recognize 2.88MB boot images (eg
Thinkpad 600 series, and possibly other Thinkpads).

This would be a really nice thing to do to the standard NetBSD ISO
images - there are many machines that can't do a boot-from-CD
installation with the current setup.