hello rd1,
don’t you already had a success by flashing secure image to the fused device?
here’s our steps to create secure image.
for example,
$ sudo BOARDID=3448 BOARDSKU=0002 FAB=200 FUSELEVEL=fuselevel_production ./nvmassflashgen.sh --noburn -x 0x21 -y PKC -u <key.pem> jetson-nano-devkit-emmc mmcblk0p1
after that, use the image to flash the non-fuse board,
$ tar xpvf mfi_jetson-nano-devkit-emmc.tbz2
$ ./nvmflash.sh --showlogs
it report Boot Rom communication failed
due to incorrect process.
so, please flash secure image to a fused board, thanks