@audionek
many thanks for your explanation but I have some confused ideas.
at the moment i have my octagon 1028 with loader 504 and pkt installed and i would build a neutrino image with loader 6.00 from max-git
As i read in your first post the max-git is update for build from kernel 214 a loader 6 image no need update with your build_env file and if i understand correctly
so no need change MTD_CONCAT into the config patch file only build the new 214 firmware and at the end i have loader 6 ready to flash.
In your second post i read that we need select at build time the loader applying the configure patch and only put the patch file from first post.
I would know at the end of build i need so your at7500_L600.sh with other your first post files and directory or at the end of build and after i apply the patch can build the ird file with max-git flash at7500 flash script because i see that with max-git flash-script i have an ird with 23030000.
Sorry for my bad english i hope you have understand my situation.
Thanks and regards.