Subject: Re: How does a PC boot from floppy?
To: None <grunza@ulticom.com>
From: Simon Burge <simonb@netbsd.org>
List: port-i386
Date: 10/13/1999 07:56:19
"Steven Grunza" wrote:
> Hi,
> I'm thinking of creating a boot floppy for some of the systems around
> here. They are large memory (128+ MB) Pentium+ machines with Win95,
> Win98, and WinNT on them. I'd like to run them diskless without a swap,
> thus avoiding any changes to their local drives. To do this, I would
> need to boot from floppy with a floppy that handled:
>
> 1) Reverse ARP to determine IP address
> 2) TFTP to get kernel
> 3) The kernel would need to know how to do NFS mounts of all needed file
> systems.
The netboot stuff supports loading the kernel via NFS without having to
use TFTP.
> It seems that most of this code should already exist in some form or
> another. Does any one have a suggestion as to where to find the
> documentation on how to do this? I've checked the
> http://www.netbsd.org/Documentation/network/netboot/intro.i386.html
> page. The systems don't support BIOS netbooting. More information on
> the netboot.com program might be all I need. Thanks for any and all who
> can help.
If your ethernet card is supported by the standalone stuff (look at the
Makefile in /usr/src/sys/arch/i386/stand/netboot), you should be able to
make a "netboot.com" - I've got a DOS floppy, and all it's got on it is
"netboot.com" and "autoexec.bat" with "netboot" in it.
In my bootptab on the server, I've got (this file is machine generated):
.default:\
:hn:\
:ht=ether:\
:nt=timehost:\
:dn="supp.cpr.itg.telecom.com.au":\
:ds=dnsquery bindmaster:\
:to=auto:
.172_73_42_0:\
:tc=.default:\
:sm=255.255.255.0:\
:gw=172.73.42.1:\
:sa=172.73.42.42:
simonpc:\
:ha=00.10.5a.63.65.4f:\
:tc=.172_73_42_0:\
rp=/dlboot0/simonpc.root:
And under /dlboot0/simonpc.root I just extracted all the installation
sets and hand-configured a few things in /etc.
We've got a separate filesystem with all our diskless client's swap
files that dont get backup up - here's the relevent lines from the
fstab:
balrog:/dlswap /swap nfs rw
/swap/simonpc none swap sw
swap /tmp mfs rw,-s=60000
There was a thread here back in April with the subject of "netbooting
from a floppy disk bootblock" that had some info on what I did. All in
all this works well, and the PC support guys here at work don't know my
"NT only" peecee runs NetBSD 99% of the time :-)
Simon.