In message 14702144.post@talk.nabble.com you wrote:

Can anybody tell me where in u-boot source code and how is the crc32 checksum generated for the bootvars

This should be trivial to find in the source code, shouldn't it?

But the values in the bootvars section in flash do not match with the printf values? There is a crc32 command in the u-boot bootloader as well. Is that used to calculate the checksum in the bootvars section? If yes, then what option is it used with and can we replicate the same code in user space so we can edit our own files and append checksums to it at the beginning?

I think what you're trying to do is broken by design. Instead of trying to rely on internal information of U-Boot (how it stores the environment variables) you should instead use the official, documented interfaces to do what you want to do.

Instead of crafting some binary blob that holds the environment variables in some undocumented internal format, you should simply write a text file which sontains the wanted variable settings in form of "setenv" commands, then convert this text file into a script image, and finally use the U-Boot "autoscr" command to apply these settings.

Thius way you can be sure that U-Boot will compute the correct checksum itself.

Also, you have simple text files which are much easier to maintain than binary blobs.

Best regards,

Wolfgang Denk