Thoughts about handling different installation media types
My blog post about the special netinst CDs including non-free firmware
 has triggered some discussion between Joey and I. There's a few
issues that we've found, and we think they're worth sharing. Yes, I
know that we should have found these earlier, before beta time ... :-(
I think that some of these should be filed as bugs, but for now I'm
writing this all down before I forget the details. I may go through
and file these properly later.
I was assuming (and said) that you'd be able to use these firmware
netinsts simply for bootup, then move on to use a full media set to
install the rest of the system. Unfortunately, that's not the case as
it's a netinst CD and so will contain not_complete in .disk/cd_type. I
can hack things in debian-cd to make this work, but there's all kinds
of assumptions in apt-setup about media types and I don't want to
Looking through the code in apt-setup, Joey and I have found some
places where oddly specific choices are made. At the moment, Blu-rays
will show up as CDs (type "full_cd"), which will cause d-i to prompt
asking for extra discs as though you've only got a small set of
packages available. But DVDs behave differently - see
generators/50mirror. There's also special-case code to print different
messages based on the number of discs seen so far, and that code also
does differing things depending on the media type. This is a little
It would be nice to have some discussion about what's expected/desired
from the cd_type, and let's see if we can make it more generic. Should
I have an extra flag file (".disc/non_free_firmware") that we can add
code to detect here, or is that redundant?
There's also code to remove netinst entries from the final
sources.list (finish-install.d/10apt-cdrom-setup). Normally, that
sounds like an excellent idea, except...
a) it's a little fragile: it just checks for any ftp or http entry
rather than one corresponding to a proper mirror. If anybody is
using a network mirror of local packages or just security.d.o
here, they won't get to see any sources for the main base system.
Minor issue, I know...
b) for the netinst-with-firmware case, I'm thinking that it would be
lovely if we could *keep* the special netinst image in the
sources.list, but *at the end*. That way, maybe the user will be
able to reference the non-free firmware debs on that CD rather
than having to be tainted by non-free stuff from other locations.
(I admit this is very much a wishlist thing, I don't know how
sensible/feasible this might be! :-))
Steve McIntyre, Cambridge, UK. firstname.lastname@example.org
< sladen> I actually stayed in a hotel and arrived to find a post-it
note stuck to the mini-bar saying "Paul: This fridge and
fittings are the correct way around and do not need altering"