MTD: How to get actual image size from MTD partition

[Greg KH]

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.

good luck!

greg k-h