Dual Booting 64 Bit devices

Modifying filesystem

Mount System partition:

mount_apfs /dev/disk0s1s3 /mnt1

And modify fstab using nano:

cp -a /etc/fstab /mnt1/etc/fstab

nano /mnt1/etc/fstab

Change disk0s1s1 to disk0s1s3 and disk0s1s2 to disk0s1s4. (or the new system and data partitions disks based on the device.)
Press CTRL-O to save and CTRL-X to exit.

Now we have to add SEP to the second system:

cp -a /usr/standalone/firmware/sep* /mnt1/usr/standalone/firmware/

Also add the baseband firmware:

cp -av /usr/local /mnt1/usr/local

The baseband is located inside of /usr/local, and the firmware names vary across devices. We can just copy it since the /usr/local path does not exist on the new system.

Modifying data partition

Now we have to move /private/var to new Data partition:

mount_apfs /dev/disk0s1s4 /mnt2

mv -v /mnt1/private/var/* /mnt2

Next part → no-effaceable-storage