Excerpts from netbsd: 4-Sep-97 i386 boot problem der
Mouse@rodents.montre (1288*)

> But when I copied the image to a floppy (dd if=boot12G.fs bs=1228800
> of=/dev/rfd0a on a NetBSD/sparc machine)

I used "dd if=boot12G.fs of=/dev/rfd0a" on a i386.

> booting fd0a:netbsd.gz
> 958464exec: short read
> boot: fd0a:netbsd.gz: Input/output error

Boots for me without error.

> I copied the image to a NetBSD/i386 machine,
> mounted it thanks to the good graces of the vnd driver, and appended
> 337 bytes from /dev/zero to the netbsd.gz file, that being the number
> necessary to pad it to a multiple of 512

The error happens early in netbsd.gz, before even the data segment
is started. It your fix helps, then it is due to side effects imo, perhaps
rewrite of  another sector, removing a physical error.

> Known bug?  Something wrong with this hardware?  Worth sending-pr?

I think it's hardware. If verifying the image, rewriting and so one
doesn't lead to results, tell me. (I have some code which allows
to test the libsa filesystem parts in user space.)

best regards
Matthias