Re: [PATCHv4] MMC: MMC boot partitions support.

[Andrei Warkentin <andreiw@motorola.com>]

On Wed, Mar 30, 2011 at 5:46 PM, Chris Ball <cjb@laptop.org> wrote:
> Hi,
>
> On Wed, Mar 30 2011, Chris Ball wrote:
>> Hi Andrei,
>>
>> On Wed, Mar 30 2011, Andrei Warkentin wrote:
>>> Unfortunately yes, although I am open for suggestions. An idea I
>>> considered is to add a postfix for device partitions. So, for card 0,
>>> the user area will remain mmcblk0, while boot partitions will be
>>> mmcblk0b0 and mmcblk0b1, generic partitions will be mmcblk0g0, and so
>>> on.
>>
>> Like Arnd, my main concern was around naming, breaking boot setups, and
>> freaking people out by telling them that their cards have block devices
>> that they can't usually see and not making it obvious where they came
>> from.  :)
>>
>> Your "b/g" postfix solution appears to fix all of these, so I like it.
>> We still have to think about where we expect users wondering what the
>> "b" and "g" mean to go in order to find out..
>

Ok, I'll add that in. I'll add the documentation changes as well.

> Oh, one more thing -- if we go with the b/g postfix, what's the
> intuition for requiring a Kconfig entry to turn this on?  Is there
> any good argument against just turning it on for everyone, as long
> as it's not affecting mmcblk*p* naming?
>

The boot partition support (and any other XYZ partition support in the
future) so far in the patch is a Kconfig entry. So you have to want it
to get it.

The argument against turning it on by default is that someone might
figure that mke2fs-ing the boot partitions is a good way to reclaim
4MB on their rooted device,
and if they didn't realize the data was necessary for boot-up, they
will brick the device. That and people might freak out when they see
more mmcblk entries than they expected :-).

A