Your whole approach seems overkill to me. Why don;t you simply include a "saveenv" command in your update script? As long as the environment is not shifted (which seems unlikelyin your case) no other changes are needed.
oh! i didnt know this! it's an easy way to retain env variables :)
btw, when i update my u-boot in the field (for some unavoidable reason), the update_uboot script erases all the u-boot flash sectors and over writes the new u-boot.bin - what if somethings goes wrong with the communication or power while copying u-boot.bin to flash?? i may loose important settings of my product in the field! u-boot.bin can always be updated using the BDI tool! But i cannot recover the environment variables.
i can make my update_uboot script in such a way that, before erasing the u-boot sectors, it will copy the env section to some free flash sector(as a backup) , update the u-boot.bin and then call 'saveenv'. i hope this is the better way to protect my environment variables.
please let me know if someone has better idea than this. Best regards, Albert.