How do you make a bootable floppy?

[Simon J. Gerraty]

In <1289 at brchh104.bnr.ca> sld at beach.cis.ufl.edu writes:
>Is it possible (without enormous pain) to make a bootable floppy for a
>SPARCstation or a 386i?  We have about 20 386i's and in the course of a
>...

>Here is the procedure we have tried:

>1. fdformat			(fdformat knows to use /dev/rfd0c)
>2. newfs /dev/rfd0c		(or mkfs for 4.0.2 since newfs is broken)

Wish I could help more...

On SunOS 4.0.2 on a 386i I use:

mkfs /dev/rfd0c 2880 18 2 4096 512 8 5 6

The 6 at the end, is 6 revs per second (360 pm) vs the default of 60
(3600).  Without this the floppy file system gets corrupted very easily.

Even with the above, I find that no amount of sync'ing before umount
prevents the diskette from becomming corrupted after a while.   It may be
necessary to leave the diskette _in_ the drive for some time after unmount
(and after the drive light goes out).

We had a set of boot floppies for one of our 386i's but of course it
failed (before I made a backup).  I'd like to be able to make a
replacement.


>This seems to make an almost booting floppy that reads the kernel file and
>starts most of the device drivers.  On a SPARCstation the process dies
>with the following messages:

>	fd0: read failed (40 10 0)
>	fd0: data overrun/underrun
>	panic: vfs_mountroot cannot mount root

This sounds consitent with the rps param to mkfs being wrong.

>and on the 386i it crashes a few device drivers later with:

Well, I would like to hear if/when you get it working.

Simon J. Gerraty		<sjg at melb.bull.oz.au>