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Date:   Mon, 19 Jul 2021 11:28:14 +0200 (CEST)
From:   Richard Weinberger <richard@nod.at>
To:     Pintu Agarwal <pintu.ping@gmail.com>
Cc:     Greg KH <greg@kroah.com>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-mtd <linux-mtd@lists.infradead.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        Phillip Lougher <phillip@squashfs.org.uk>,
        Sean Nyekjaer <sean@geanix.com>,
        Kernelnewbies <kernelnewbies@kernelnewbies.org>
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Subject: Re: MTD: How to get actual image size from MTD partition
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Thread-Topic: How to get actual image size from MTD partition
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----- Ursprüngliche Mail -----
> Von: "Pintu Agarwal" <pintu.ping@gmail.com>
> An: "richard" <richard@nod.at>
> CC: "Greg KH" <greg@kroah.com>, "linux-kernel" <linux-kernel@vger.kernel.org>, "linux-mtd"
> <linux-mtd@lists.infradead.org>, "linux-fsdevel" <linux-fsdevel@vger.kernel.org>, "Phillip Lougher"
> <phillip@squashfs.org.uk>, "Sean Nyekjaer" <sean@geanix.com>, "Kernelnewbies" <kernelnewbies@kernelnewbies.org>
> Gesendet: Montag, 19. Juli 2021 11:09:46
> Betreff: Re: MTD: How to get actual image size from MTD partition

> On Fri, 16 Jul 2021 at 21:56, Richard Weinberger <richard@nod.at> wrote:
> 
>> >> My requirement:
>> >> To find the checksum of a real image in runtime which is flashed in an
>> >> MTD partition.
>> >
>> > Try using the dm-verity module for ensuring that a block device really
>> > is properly signed before mounting it.  That's what it was designed for
>> > and is independent of the block device type.
>>
>> MTDs are not block devices. :-)
>>
> Is it possible to use dm-verity with squashfs ?
> We are using squashfs for our rootfs which is an MTD block /dev/mtdblock44

Well, if you emulate a block device using mtdblock, you can use dm-verity and friends.
Also consider using ubiblock. It offers better performance and wear leveling support.

Thanks,
//richard