Step 1 of debian-installer

[Thierry Laronde <thierry@cri74.org>]

Hello,

I've just checkout cvs tree and have a look to the doc.

I have been studying some parts of the problems for a project that we
(cri74.org) are launching. So here are some solutions/ideas for the very
first step :

- In order to install the very first system (kernel + root) one needs enough
  memory -> if the bootloader is able to display the amount of memory
  installed, you can, at least, display a message that the mem is xxx Kb,
  and that the installation will fail with less than, say 8 Mb ; for x86,
  GRUB can do that (but, at the moment, it doesn't allow conditionnal, only
  displaying a message saying that the next action might fail if there is
  not enough memory);

- Size of a floppy is the critic point. You can have more space on a HDD,
  by playing with the number of sectors. But you need to have a bootloader
  able to identify the CHS parameter in order to access and load the data
  (kernel and root fs); for x86, Lilo can do that, and there is a patch to
  GRUB to allow this too;

- Part of the sectors are "lost" for the fs; if one has a bootloader able to
  install itself without a fs, and able to retrieve data (blocklist) without
  the fs, you can "save" these sectors by putting everything on a raw
  floppy; for x86, GRUB can install itself, and boot with blocklist
  notation; it is able to load kernel and initrd this way too;

- The bootloader has a size; if one can use the bootloader installed on the
  floppy as the data to install as the bootloader for the hard disk, the
  same data is used twice, then there is no need to duplicate the bootloader
  in the initrd; for x86, GRUB can be handled this way;

- for x86, GRUB can be used for recovery (you are able to load any kernel
  found somewhere); so this is, automatically, a rescue disk.

Cons : all of this stuff is, at the moment, very x86 specific. But the
floppies have to be machine dependent in some way...

FWIW,
-- 
Thierry LARONDE, Centre de Ressources Informatiques, Archamps - France
http://www.cri74.org
PingOO, serveur de com sur distribution GNU/Linux: http://www.pingoo.org