http://c25o7knygjm3m67jy27yuynvv4pkfi25naucscmh4ubq2ggiig3v57ad.onion/en/guix-on-android.html
One solution consists in
installing the content of the binary tarball on an existing partition (because
you can't modify the partition layout easily) that has enough free space,
typically the data partition. Then this partition is mounted on /var and /gnu . Before that, you will need to find out what the data partition is in
your system.