RE: geometry output / floppy chainloading from El Torrito

[tlaronde]

En réponse à Treutwein Bernhard <address@hidden>:

Hi,

> Salut Thierry,
> 
> thanks for:
> > -----Original Message-----
> > From: address@hidden [mailto:address@hidden 
> > Sent: Thursday, January 09, 2003 9:47 PM
> [...]
> > > boots again (correctly ?) the boot record from the El Torrito
> > > floppy image.
> > 
> > (fd0) is indeed the floppy image on the El Torito CD.
> > 
> > The problem I think with (fd1) ("real (fd0)") is that you 
> > have an "old" version of GRUB specifying the booting device 
> > as (fd0). Then the stage1 on (fd1) calls a stage2 on (fd0) 
> > that is on the floppy El Torito image. Hence this fails. If 
> > you upgrade your stage1 on the floppy (not specifying explicitely
> > the booting device) this should work.
> > 
> 
> hmm, that may be, on the CDROM is a 0.5.96.1 and on the floppy
> is a fresh 0.93 from the cvs last week.
> 
> But - please correct me if I it should be different - if I boot 
> from floppy I see only the (fd0) logical and physical floppy. 

Yes, indeed. If you boot from the CD, you should/may see still (fd0) and
(fd1) [El Torito is "running"] from GRUB chainloaded from the floppy. If you 
boot from the floppy directly, you will see only the real floppy.


The problem I could see was more with stage1 _on the floppy_ than GRUB on
the CDROM. I have not given a look to the way GRUB chainloads. If and only
if GRUB fakes the BIOS interrupt, and reset nothing, the GRUB on the floppy
should "see" the two floppy drivers (El Torito and real). If GRUB resets 
something, then you need to have a stage1 on the floppy which specifies the
drive to call (fd0 in this case since El Torito emulation will have 
disappeared; if the stage1 on the floppy call the booting device by default,
and the booting device is fd1 but this one has disappeared via the 
chainloading everything goes wrong). I will try to give a look to the
source in a few days.

Cheers,