Chainloading GRUB2 from Lilo

[Tim Booth <avarus@fastmail.fm>]

Hi All,

Sorry to clog up the developer list with my questions but I've scoured
the documentation and not found an answer.

I've hit this known problem:
http://sourceforge.net/apps/mediawiki/bootinfoscript/index.php?title=Boot_Problems:Windows_Writes_To_MBR

Where broken software on Windows is clobbering GRUB2.  Modifying the
corporate Windows installation is not an option, so I'm trying to use
Lilo in the MBR and immediately chainload Grub.

Now I could install Grub into the (Ubuntu) Linux partition, but it seems
rather simpler to just ask Lilo to chainload core.img.  As far as I can
tell, the only way to do this is to use lnxboot.img, telling lilo that
core.img is an initrd. - ie. like this:

---my /etc/lilo.conf---
# Very basic LILO chainloader config
boot = /dev/sda
lba32
default = chainload_grub2
timeout = 0

image = /boot/grub/lnxboot.img 
  append = "prefix=(hd0,5)/boot/grub"
  root=/dev/hda5
  initrd = /boot/grub/core.img
  label = chainload_grub2
---end---

But when Grub loads the prefix is set to (hd0,1)/boot/grub and I just
get a recovery prompt and have to do:

set prefix=(hd0,5)/boot/grub
insmod normal
normal

So, is there any way to get the correct prefix passed through?  I know
there are other ways to attack this problem, but as the fix needs to be
maintained on many machines I'm looking for something as simple as
possible, and this is the simplest I can come up with, so I thought I'd
ask this list before abandoning the idea completely.

Cheers,

TIM

-- 
To Err is human.
To Arrr is Pirate!