Re: Guidance on conflicts between GNU GRUB and proprietary software

["Vladimir 'φ-coder/phcoder' Serbinenko" <phcoder@gmail.com>]

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On 09/28/2010 10:07 PM, Lennart Sorensen wrote:
> On Tue, Sep 28, 2010 at 09:43:25PM +0200, Vladimir 'φ-coder/phcoder' Serbinenko wrote:
>   
>> GPT has new types.
>>     
> GPT has an msdos partition type for itself for use in hybrid setups.
> I know GPT partition tables have new types, but GPT itself has a type
> reserved in the old dos partition table.
>   
You probably mean the 0xee type. But it's used only to mark the whole
space as used. In our case it's a partition which is identified to have
all the data deleted. Let's just take a famous collision between Solaris
and Linux swap. I doubt that any of them willingly choose the type in
order to collide with other. If Linux relied solely on the partition
type to identify its swap it would be a disaster for dual-boot system.
>   
>> in msdos there are only 255 possible types. Some are known to be used by
>> well known software but during 10 years of no central body for this and
>> everybody willing a type just taking one in self-service I think every
>> single type is used by either widely known or mostly unknown software.
>> And destroying someone's hobby OS would be a bad thing.
>>     
> And not having a reliable grub on actual used OSs isn't a bad thing?
> Someone's hobby OS could change if it was an issue.
>
>   
Destroying the data which is on its rightful place is bad independently
what you use the place for, how important your usage is or how
"unimportant" you judge the current occupant.
I believe it's possible to have something something much more reliable.
We could have a tool grub-mkembed (analog of mkswap) which would mark
the partition as available for GRUB embedding (perhaps in addition of
checking type). This signature must be written in a way to be
overwritten when formatted in known filesystems
>> GRUB has a design principle of being cross-platform installable.
>> Moreover the same disk can contain multiple grub installation. I
>> personally regularly move the disk between yeeloong and amd64 laptop,
>> well it has only one GRUB since on yeeloong my GRUB is in flash but it
>> could easily have one on disk too.
>>     
> If two architectures expect sector 0 to contain boot code, then that
> can't work.  I certainly would not consider that a worthy design goal
> compared to lots of other things.
>
>   
Some architestures are incompatible because of such reasons but many
others don't conflict in such ways.
When you abandon a design goal or give an exception you first have to
make sure that there is no way to reconcile the given features.
Just one example: I'm ready to give an exception to multiterm design in
order to get the features required for ubuntu CDs but first I discussed
in order to find compromise which would result in less mess on codepath
intersections and it looks like there is actually one.
In this case taking PReP partition type would be unfounded.


-- 
Regards
Vladimir 'φ-coder/phcoder' Serbinenko



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