Re: [Design] nested partitions: Unify grub_partition and grub_disk

From: Robert Millan <rmh@aybabtu.com>
To: The development of GRUB 2 <grub-devel@gnu.org>
Cc: "Yoshinori K. Okuji" <okuji@enbug.org>
Subject: Re: [Design] nested partitions: Unify grub_partition and grub_disk
Date: Mon, 13 Apr 2009 16:00:37 +0200	[thread overview]
Message-ID: <20090413140037.GD12170@thorin> (raw)
In-Reply-To: <49E1126D.4050604@gmail.com>

On Sat, Apr 11, 2009 at 11:58:05PM +0200, phcoder wrote:
> Ping. Is it ok for me to implement it this way?

I'd really like it if Okuji could give his impression on this one, if
possible.

> phcoder wrote:
>> I forgot to speak about another question: partition naming. I see 2  
>> possibilities
>> 1) purely numeric unified naming scheme. It means that
>> (hd0,1,a) becomes (hd0,1,1)
>> On one hand mixed number-letter scheme is similar to what freebsd uses  
>> but on the other hand numerical scheme is versatile and allows 
>> unlimited nestedness. And I don't see why we would use a scheme 
>> specific to one of many supported OSes.
>> 2) Every partition map is allowed to pick the name that it likes as 
>> long as it contains no comma. In this way we would need to keep  
>> partition-name parsing functions in partitition map modules. It means  
>> that this code would be duplicated. But this scheme is better in the  
>> cases when partition map has no numbering scheme but instead has labels 
>> attached to partitions. But in this case IMO search command should be  
>> used find the partition
>>
>> I personally would prefer the first way
>>> Also an interesting question is how would "has_partitions" field be
>>> handled in this scheme.
>>
>> Just ignored. It's actually used only to optimise some code out based 
>> on the assumption that some media has no partitions. Performance gain 
>> is negligible but if this assumption doesn't hold true grub won't be 
>> able to access the partitions which are really here. Famous example is 
>> a cdrom. Most people would assume that cdrom has no partitions. But on  
>> powerpc bootable cdroms use APM
>>
>>
>>
>
>
> -- 
>
> Regards
> Vladimir 'phcoder' Serbinenko
>
>
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>

-- 
Robert Millan

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