Re: Guidance on conflicts between GNU GRUB and proprietary software

["Grégoire Sutre" <gregoire.sutre@gmail.com>]

On 09/29/2010 00:11, Vladimir 'φ-coder/phcoder' Serbinenko wrote:

Let me try to explain more clearly what I have in mind.  In the GPT
case, we have a dedicated partition ID for bootloader software.  This
makes things simpler.  If we had such a dedicated partition ID in the
MSDOS case, then a lot of embedding problems would (a priori) go away.
So it's worth trying to ``establish'' such a partition ID for MSDOS
partitions.  And good candidates are partition IDs that are already
(almost exclusively) used by some bootloader software(s), because

- those partitions are very likely to only contain bootloader code
   and configuration, so the risk of data loss when installing GRUB
   is minimized.

- OSes and partitioning software may already know about them, which
   would limit the risk of losing the embedded GRUB code.


>> If we really want to embed in an MSDOS partition, selecting a
>> partition type that is already used for similar purposes is IMHO
>> our best option. This would be a step in a direction to set a
>> ``standard'' MSDOS type for boot partitions.  We don't need one
>> partition type per boot-loader software anyway.
> OS/2 used type 0x0a. If someone wants to install the OS/2 on his
> computer (I wouldn't attempt it on anything newer than Pentium 3)
> then he probably wants to chainload it (direct loading OS/2 would
> require much work and has no point, adapting ntldr would be possible
>  though, but I wouldn't spend any time on it). So he needs 2 boot
> managers. Probably there are other similar cases as well.

I didn't mean that we only need one partition for bootloaders.  What I
mean is that we only need one partition type.  Such as, if you install
two Linux distributions, you would have the same ID for all your Linux
partitions.

But I agree that, if we had two MSDOS partitions with the same
``bootloader'' type, then grub-install shouldn't blindly take the first
one.  Still, isn't this what happens in GPT case, when there are two
BIOS Boot partitions?  Or maybe, in the GPT case, there is no point in
having several BIOS Boot partitions?

Anyway, I'm sure that we can find solutions to make sure that, in a
non-interactive mode, a new GRUB installation only overwrites a previous
GRUB installation.


> Deleting some other bootloader may also appear unfair and lead to
> data loss if its partition contained anything useful.

In the GPT case, doesn't grub-install delete existing data in the GPT
BIOS Boot partition?


> I don't mind sharing the embedding partition on the rule "who gets
> MBR gets this bonus,

I didn't see it this way.  I assumed we could have different bootloader
software in different partitions of the ``bootloader type''.


> all possible occupants have to implement multiboot to be chainloaded
> if necessary" but former users of partition type may disagree.

Yes, of course, if we try to go this route, we would have to discuss
it with former users of the partition type.

Grégoire