I'm not completely sure about this, but my speculation is:
-The last time someone worked on the makefiles for the boot floppies,
the kernel was much smaller and over the years has grown in size
through changes to the default options and codebase.
-PReP is not a popular port, so not much attention is given to it.
This allows for things like this to slip under the radar and usually
need to be fixed by folks that use the port.
-Not many users of this port probably use floppy boot, most probably
use the network boot method instead or boot from an install CD.
-CD booting should work, but the last time I checked and if I remember
correctly, it defaults to rs232 console output and appeared to be
broken (on my hardware).
To get around that issue, you'll need to create a custom CD ISO image
that doesn't use the COM boot loader, but the regular one instead.
https://www.netbsd.org/docs/guide/en/chap-inst-media.html
You would need to modify this file in in the source:
https://cdn.netbsd.org/pub/NetBSD/NetBSD-release-8/src/distrib/prep/cdroms/installcd/Makefile
On line 4, change "sysinst_com0.fs" to "sysinst.fs", this will allow
you to do a regular non-rs232 install.
The i386 port looks to have working boot floppies, but they use a
special boot loader that allows the image to be spread across a series
of floppies.
https://cdn.netbsd.org/pub/NetBSD/NetBSD-release-8/src/distrib/i386/floppies/common/Makefile.bootfloppy
I don't see that boot loader available for PReP, so it would probably
need to be ported (if possible) to make floppy boot work once again.
If you get the installation to work, but the machine does not boot
past a blinking cursor on a black screen, this thread may be of
interest to you:
http://mail-index.netbsd.org/port-prep/2018/02/05/msg000129.html
The default boot image the installer writes to the PReP partition does
not seem to work, but you can get it to work by using the
sysinst_small image instead.
The regular sysinst image may work too, but I don't remember if I
tried that one.
On 2/17/19 5:11 PM, Alan Perry wrote:
Hi,
I need to clobber the HDD on a RS/6000 7043-140 and I am doing it by
installing NetBSD over what's there.
How does one create a boot floppy under NetBSD/sparc? The NetBSD/prep
floppy .fs files are all larger than a 1.44M floppy and the RS/6000
throws an exception when I boot it from a floppy that is a simple dd
of the .fs images. What should I be doing to create a floppy that works?
alan