[PATCH 1/2] ubi: mount partitions specified in device tree

[Ezequiel Garcia]

On 18 June 2016 at 16:35, Hauke Mehrtens <hauke at hauke-m.de> wrote:
> On 06/18/2016 09:30 PM, Richard Weinberger wrote:
>> Am 18.06.2016 um 21:17 schrieb Hauke Mehrtens:
>>> This makes it possible to open a ubi layer in device tree, this is
>>> helpful when the rootfs is on a ubi layer. It loops though all mtd
>>> partitions and mounts the partition which is compatible with
>>> "ubi,volume". The same was only possible with kernel command line
>>> arguments before.
>>>
>>> Signed-off-by: Hauke Mehrtens <hauke at hauke-m.de>
>>> ---
>>>  Documentation/devicetree/bindings/mtd/ubi.txt | 33 ++++++++++++++
>>>  drivers/mtd/ubi/block.c                       | 63 +++++++++++++++++++++++++++
>>>  2 files changed, 96 insertions(+)
>>>  create mode 100644 Documentation/devicetree/bindings/mtd/ubi.txt
>>
>> Some time ago I thought about an UBI DT binding too, but
>> I have been told that device tree is only for describing the hardware
>> and nothing else.
>> So I fear this will be rejected by DT folks.
>
> There are some devices on the market that are storing the root file
> system in an ubi layer.
> To make this work there are currently two options.
> 1. patch the kernel to specify which partitions to open in the code.

I wouldn't go as far as to claim this an option.

> 2. provide some kernel command line parameter which specifies what to open.
>

There's another option: use an initramfs, where you can do whatever you want
to find your UBI and mount it.

Frankly, I don't see a real need for this in the devicetree, other than solving
someone's particular workflow/use case.
-- 
Ezequiel García, VanguardiaSur
www.vanguardiasur.com.ar