[OE-core] Contents of non-rootfs partitions

[Kristian Amlie]

On 23/11/16 09:40, Enrico Joerns wrote:
> On 11/22/2016 12:54 PM, Kristian Amlie wrote:
>> On 22/11/16 12:10, Patrick Ohly wrote:
>>>> ...
>>>
>>> All of these introduce some special mechanism. Let me propose something
>>> that might integrate better with the existing tooling:
>>>
>>> The "rootfs" directory gets redefined as representing the entire virtual
>>> file system. When creating a disk image, it gets split up into different
>>> partitions based on the image configuration.
>>>
>>> For example, the /home or /data directories in the rootfs could hold the
>>> content that in some image configurations goes into separate partitions.
>>>
>>> The advantage of this approach is that the tooling for staging content
>>> for image creation does not need to be changed. The same staged content
>>> then can be used to create different images, potentially even using
>>> different partition layouts.
>>
>> That's a very good idea. I think it beats all of my suggestions!
> 
> I totally agree with this solution, because it is the same approach we
> are already using for several years.

Good! Sounds like there are several votes in favor of this proposal then.

> Instead of wic we are using the genimage tool
> (http://public.pengutronix.de/software/genimage/) together with a Yocto
> class for easing image creation, but its pretty much the same concerning
> its base purpose.
> 
> We called the option to split up 'mountpoint' while assuming that the
> splitted partition will be mounted to the same location in the file
> system it was taken from.
> 
> An example configuration would look like this (stripped down to the
> essential parts):
> 
>   image my-disk-image {
>           [...]
>           partition root {
>                   image = "rootfs.ext4"
>                   [...]
>           }
> 
>           partition home {
>                   image = "home.ext4"
>                   [...]
>           }
>   }
> 
>   image rootfs.ext4 {
>           [...]
>           mountpoint = "/"
>   }
> 
>   image home.ext4 {
>           [...]
>           mountpoint = "/home"
>   }
> 
> Maybe a similar approach could be used in wic, too.

Yes, this looks very similar "in spirit" to what I'm thinking of right now.

-- 
Kristian