I tried multiple configs ( with or without ramdisk support, tring with ext4 squashfs ... etc ), my issues is that no updates seems to take place. sysupgrade in console shows is as follows ( i have a screenshot video, but it may not be easy to read, so i typed in all the messages shown on screen )
"Image metadata not present"
"Reading partition table from harddisk"
"Extract boot sector from the image"
"Reading partition table from image"
.... ( files to be kept for the update, such as /etc/config/network )
"Commencing upgrade.Closing all shell sessions"
[ kernel message ] "drop_caches : 3"
[ kernel message ] "ext4fs ( sda2 ) re-mounted, Opts: (null)"