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Date:   Fri, 16 Jul 2021 18:26:56 +0200 (CEST)
From:   Richard Weinberger <richard@nod.at>
To:     Greg KH <greg@kroah.com>
Cc:     Pintu Agarwal <pintu.ping@gmail.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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References: <CAOuPNLjzyG_2wGDYmwgeoQuuQ7cykJ11THf8jMrOFXZ7vXheJQ@mail.gmail.com> <YPGojf7hX//Wn5su@kroah.com>
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: "Greg KH" <greg@kroah.com>
> An: "Pintu Agarwal" <pintu.ping@gmail.com>
> CC: "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>, "richard" <richard@nod.at>
> Gesendet: Freitag, 16. Juli 2021 17:41:01
> Betreff: Re: MTD: How to get actual image size from MTD partition

> On Fri, Jul 16, 2021 at 12:12:41PM +0530, Pintu Agarwal wrote:
>> Hi,
>> 
>> Our ARM32 Linux embedded system consists of these:
>> * Linux Kernel: 4.14
>> * Processor: Qualcomm Arm32 Cortex-A7
>> * Storage: NAND 512MB
>> * Platform: Simple busybox
>> * Filesystem: UBIFS, Squashfs
>> * Consists of nand raw partitions, squashfs ubi volumes.
>> 
>> 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. :-)

Thanks,
//richard