Re: [PATCH] nested partitions

[Vladimir 'phcoder' Serbinenko]

On Fri, Jul 31, 2009 at 9:48 PM, Vladimir 'phcoder'
Serbinenko<address@hidden> wrote:
>>> What makes this experimental and dangerous?  Can you send in a patch
>>> that isn't?
>> Only that I touch core size
> *core functionality
>> and when I submitted it, it was only few
>> days old. Now I use it for over a month and haven't hit any problem
>> The typical case of the problem it solves is Solaris. When installed
>> on x86 its partition is subpartitioned. Because of that current grub
>> can't access its filesystem even if it's UFS or even when ZFS module
>> is loaded. sun_pc subpartitioning style will be a subject of separate
>> patch.
>
> The proble it doesn't solve is when 2 partition labels pretend to
> describe the same region. Solaris during install dd'es MBR to its
> partition that it subdivides in further paritions. This way the
> parition seems to have 2 valid subpartitioning tables. I think the
> most sane way to handle this is to introduce partition labels
> priority. Fortunately thanks to Bean we have priority-list handling
> function so it should increase the size of core for a lot. Numbers
> will be available when I test it.

Mainstream core with pc+fat+biosdisk: 26179 bytes
Core with nested parition support  with pc+fat+biosdisk: 26027 bytes
Core with nested parition support  with pc+bsdlabel+fat+biosdisk: 26392 bytes
As you can see core size decreases if no bsdlabel support is needed
but increases otherwise. Fortunately BSDs are unlikely to be on Reiser
or LVM (although may be on ZFS)
After additionally removing 'data' field w/o bsdlabel: 26000
After additionally removing 'data' field w/ bsdlabel: 26352
After additionally adding priority support w/o bsdlabel: 26006
After additionally adding priority support w/o bsdlabel: 26367

After additionally not inlining grub_partition_get_start w/o bsdlabel: 26022
After additionally not inlining grub_partition_get_start w/ bsdlabel: 26363
So I prefer to let grub_partition_get_start inlined


-- 
Regards
Vladimir 'phcoder' Serbinenko

Personal git repository: http://repo.or.cz/w/grub2/phcoder.git