[U-Boot] Integity validation (checksum) of a squashfs root file system

[Pascal Levesque]

Hi M,

sha1sum does provide a console output but nothing that could be used for an 
automated check like crc32 -v...

Pascal

-----Original Message----- 
From: Marek Vasut
Sent: Monday, February 06, 2012 11:34 AM
To: u-boot at lists.denx.de
Cc: Pascal Levesque
Subject: Re: [U-Boot] Integity validation (checksum) of a squashfs root file 
system

> Hi,
>
> I would like to validate the integrity (checksum) of a squashfs root file
> system before starting Linux.
>
> Current strategy I am using is:
> - Wrap squashfs rootfs inside a u-boot image
> - TFTP download on the target
> - Download validation using iminfo
> - Save squashfs rootfs in flash without the image header (Linux failed to
> load squashfs rootfs if u-boot image is present)
>
> Problems:
> - I need to hardcode squashfs rootfs offset in u-boot image in order to be
> able to flash it - U-Boot image header information (size, crc, ...) is
> lost after a reboot. It is not possible to check the integrity of the
> flash content.
>
> I would like to save some fields of u-boot image header (size, crc, ...)
> in u-boot environment variables. And then do an integrity check at boot
> time.
>
> I have not find a way to extract those fields and save them without
> changing u-boot code. I have added some code to “iminfo” command to set
> environment variables for CRC, size, payload offset, timestamp.
>
> Is it an acceptable way of doing it?
> Is there a better way of doing it?
>
> Thanks in advance,
>
> Pascal

Use sha1sum integrated into uboot and stick it at the end?

M