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

6 Feb 2012

      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@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