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Subject: Re: [PATCH 2/5] mtd: block2mtd: Add support for specifying MTD write
 size and subpage shift
To: Pavel Machek <pavel@ucw.cz>
Cc: =?UTF-8?Q?Pali_Roh=c3=a1r?= <pali.rohar@gmail.com>,
        David Woodhouse <dwmw2@infradead.org>,
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 <fa265d04-07b4-0ed3-9b51-c2026f7015db@nod.at> <20170605112145.GE14675@pali>
 <ad488af9-a6c5-7795-87a2-87e610dd2121@nod.at> <20170605112508.GF14675@pali>
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From: Richard Weinberger <richard@nod.at>
Message-ID: <8440a46a-0ba2-b00f-e55b-d0a0fa9b8aa6@nod.at>
Date: Sun, 18 Jun 2017 12:11:40 +0200
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Pavel,

Am 18.06.2017 um 12:06 schrieb Pavel Machek:
> Hi!
> 
>>>>>> Am 02.06.2017 um 17:43 schrieb Pali Rohár:
>>>>>>> It is needed for creating emulated devices suitable for using in UBI layer
>>>>>>> and with UBIFS.
>>>>>>
>>>>>> Why?
>>>>>
>>>>> ubifs depends on write size of nand. And without those parameters as
>>>>> specified in cover letter I'm unable to mount N900 rootfs image exported
>>>>> via block2mtd. ubifs reject such image.
>>>>
>>>> Hmm, so you render block2mtd into a semi-NAND chip? :)
>>>
>>> Probably you can call it like that. But it is still MTD device...
>>
>> This is what I meant in my other mail.
>> You add NAND specific properties but still denote it as MTD_RAM/ROM.
>> I'm not sure whether this is a good idea.
> 
> Can you suggest any other way for Pali to mount rootfs image on his
> PC?

Are you my micro manager? ;-)

As stated in my other mail, we have nandsim and there is work going on
to allow specifying arbitrary NAND sizes.
An alternative approach can be found here:
https://lkml.org/lkml/2016/5/12/296

Thanks,
//richard