Syslinux - Oct 2003 - Important feature missing: Floppy booting from 2 disks

Hi list,

I've used sys & pxelinux now many times, it's really a useful toy. I
found
esp. syslinux very helpful as it allows to COMPLETELY boot from multiple
disks. However, I could never use a 'vanilla' syslinux for that. I'm
doomed to use Distributor patched versions, which I don't really like. Why
is that? Read on:

Well, I can't manage to boot of a 1.44 MB floppy. I simple don't manage
to
squeeze a useful modern kernel & initrd on that. Don't tell me I'm
the
only person with that problem. Yes, I know: CD or PXE boot is much better,
but there are situations where you need a floppy. A very useful
application for example are the RemoteInsightBoards of Compaq/now HP
servers. They allow to upload diskimages you can boot remotely w/o any
direct access to the system BUT it uses a BIOS emulation.  Hence, a two
disk syslinux boot combo (one disk kernel, one initrd) is perfect. Normal
loading of initrd doesn't work as the linux kernel always goes to the
floppy hardware directly. This way a plain kernel disk (just dd the kernel
onto it) has no chance to work, for example.

Distros, esp. Suse, use a patched syslinux, which prompts and allows a
diskchange for a 2nd disk before loading initrd images.

What I desperately need is a config-file option (or some automatic
mechanism if initrd image is not found on the disk) to show a prompt and
wait for a key PRIOR to loading the initrd image. This way I could use
plain syslinux and don't need to use 'hacked' Distros bootdisks with
plenty of other unwished effects builtin.

Ideally prompting and the message should be configurable, maybe even on a
by image basis, but that's only cosmetical. BUT: There should be a way to
stop and wait for a key AFTER loading the kernel but BEFORE loading the
initrd.

I'm under the impression you can't do that with the 'official'
syslinux.
If I'm wrong, please flame ahead. I can't really understand why this
option is missing, this seems such a fundamental issue to me.
[Note: with the new syslinux compilable under linux, I might be able to
help myself, when I'm going to setup my next install images]

Best Regards,
Michael.

--

Michael Weller: eowmob at exp-math.uni-essen.de, eowmob at
ms.exp-math.uni-essen.de,
or even mat42b at spi.power.uni-essen.de. If you encounter an eowmob account on
any machine in the net, it's very likely it's me.

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hello...

Dr. Michael Weller wrote:
| Well, I can't manage to boot of a 1.44 MB floppy. I simple don't
manage to
| squeeze a useful modern kernel & initrd on that. Don't tell me I'm
the
| only person with that problem. Yes, I know: CD or PXE boot is much better,
| but there are situations where you need a floppy.

This Feature Request was on this list once before.
Check the List Archives (03/2003) for the thread
"Syslinux: Multi-Disks [feature]".

I suggested a workaround to the asking ROCK Linux maintainer (Clifford
Wolf... He has built a package from it:

~ Clifford Wolf wrote:
| Just FYI: I've create a template disk image + small shell script for
| creating a multi-disk linux boot floppies for kernels and/or initrd's
| with a size > 1.44 MB. It's based on FreeDOS Beta 8, the XMSdsk ramdisk
| and Loadlin:
|
| 	http://www.rocklinux.org/people/clifford/MDLBL/
|
| I primary wrote it for ROCK Linux <www.rocklinux.org> but it might be
| usefull for everyone who wants to boot larger (2.5) kernels from floppies.

bye
Christian
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.2.1 (MingW32)
Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org

iD8DBQE/iu802gF1h3CVOsMRAlqHAKCyQbxoLNeOqgwxJQ3Pc5x2rPpgcQCg+778
JykioFWl1NKPmvINViHTl8M=TA92
-----END PGP SIGNATURE-----

Dr. Michael Weller wrote:
> 
> Distros, esp. Suse, use a patched syslinux, which prompts and allows a
> diskchange for a 2nd disk before loading initrd images.
> 
Suse does.  Noone else, to the best of my knowledge.

I know this is a highly requested feature.  It's unfortunately rather
complex to support in a sane way.  SYSLINUX code assumes pretty strongly
that its entire filestore is always accessible; that doesn't mean it
can't be dealt with (there are several ways to do it), but all pretty
much require significant restructuring of the SYSLINUX code.

	-hpa

Another way to deal with this stuff is to load a very small initrd which
requests the second floppy and loads it.  The small initrd only needs to
contain a single binary, which can be compiled and linked against klibc
for very small size.

If so, I would recommend loading the second floppy into a ramfs/tmpfs
instead of a ramdisk, especially since ramdisk support will probably be
discontinued in Linux 2.8.

	-hpa