[OE-core] Contents of non-rootfs partitions

[Kristian Amlie]

On 23/11/16 08:26, Khem Raj wrote:
> 
>> On Nov 22, 2016, at 11:13 PM, Kristian Amlie <kristian.amlie at mender.io> wrote:
>>
>> On 23/11/16 00:45, Khem Raj wrote:
>>> Firstly, it needs to be defined what the data partition is about.
>>> 1. is it some pre-initialized/seeded data that can then be modified during
>>> subsequent boots ?
>>> 2. Is it read-only data which is then used to populate r/w data segments in
>>> RAM during boot
>>> 3. is it data that does not change over the course of install and reboots of
>>> the device
>>
>> It's preseeded, but modifiable data, that survives complete rootfs
>> updates. IOW if you overwrite either of your A/B rootfs partitions, the
>> data partition and its content survives.
> 
> at some point this data segment will be seeded.
> think of factory case. 

The creation of the initial partitioned image for the memory card
preseeds the data partition. This is meant to be used in initial factory
flashing (by which I mean literally "at the factory", not the factory
reset button). Subsequent rootfs updates would not touch the data partition.

> So in such a case updates should not touch them unless user does a factory reset
> which should clean it up

Factory reset is not covered in my suggestion. While also important, I
consider this a separate feature, which would require cooperation by the
running OS. I hope it's acceptable to keep this out of the first patchset?

-- 
Kristian