Message-ID: <4FB29BF9.7050200@nod.at>
Date: Tue, 15 May 2012 20:10:01 +0200
From: Richard Weinberger <richard@nod.at>
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To: Subodh Nijsure <snijsure@grid-net.com>
CC: linux-mtd@lists.infradead.org, Heinz.Egger@linutronix.de,
        tglx@linutronix.de, tim.bird@am.sony.com, linux-kernel@vger.kernel.org,
        dedekind1@gmail.com
Subject: Re: [RFC v4] UBI: Fastmap support (aka checkpointing)
References: <1337101871-31181-1-git-send-email-richard@nod.at> <4FB296EA.5090104@grid-net.com>
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Hi Subodh,

Am 15.05.2012 19:48, schrieb Subodh Nijsure:
> Hello Richard,
>
> On 05/15/2012 10:11 AM, Richard Weinberger wrote:
>> v1: https://lwn.net/Articles/481612/
>> v2: https://lwn.net/Articles/496586/
>> v3: Didn't release it to linux-mtd
> Will kernel that has older UBI drivers be able to mount and update the
> UBI volumes that have been created with checkpointing feature?

Of course!

> Say I have bootrom that has 3.0.X kernel that has no knowledge of UBI
> checkpointing, and my flash /dev/mtd2 has UBI volume with checkpointing
> enabled. Will this bootrom be able to attach /dev/mtd2 and mount UBI
> volume and read/write files on it?

Sure!
Your bootrom will scan the UBI volume and detect two unknown internal
volumes with compat=delete in their volume headers.
So, it will delete the two fastmap volumes and continue scanning.
It can alter the volume and so on.

Thanks,
//richard

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