Refer to manual chapter 2.3 internal storage installation of EOS-JNX.
Refer to SOP video. Take 256Gb m.2 SSD for example.
format your storage as ext4
copy the files
sudo rsync -axHAWX --numeric-ids --info=progress2 / /media/adlink/ssd
Modify /boot/extlinux/extlinux.conf in emmc, emmc, emmc !!!
APPEND ${cbootargs} quiet root=/dev/nvme0n1p1 rw rootwait rootfstype=ext4
Reboot