Jolla Android On SD-Card

Table of Contents

Summary #

The Jolla has 16 GB internal disk space which is filled by Android apps like OsmAnd and Spotify pretty fast.
Thus I’ve developed a way to move the data of these apps to sd-card.

Main #

All of the following commands have to be run as root.
Thus you have to be careful otherwise you’ll break your phone.

Warranty There is no warranty that this setup works for any system which provide the dependencies listed below. I'm just providing these information because it worked for me. If you have questions you can leave a message here but I decide whether I'll answer and help or not.

If you follow these instructions you’ll move all data saved by Android apps running on the SailfishOS of a Jolla to the sd-card of your phone.

That way you might use up to 64 GB of disk space for maps, media files and everything else stored by Android apps.

Dependencies #

a Jolla phone ;D
SailfishOS >= 1.0.7.16 (earlies versions might work but aren’t tested)
Dev-Mode enabled
password to become root
SD-Card with enough space
some Linux knowledge

Instructions #

The following instructions use the following settings:

sd-card contains 1 partition
the partition device is mmcblk1p1

If your setting differs from these you have to change the corresponding commands.

insert the sd-card into your phone
start terminal
change to root user: devel-su
check whether card was found: ls /dev/mmcblk1
- the card was found if the output is /dev/mmcblk1
- if an error is thrown the card wasn’t found -> you have to reboot your phone

check whether the card is mounted mount | grep mmcblk1

the card is mounted if the output is like

/dev/mmcblk1p1 on /media/sdcard/<UUID_of_partition> type btrfs (rw,nosuid,nodev,noexec,noatime,dirsync,thread_pool=4,ssd,noacl,space_cache)

the card isn’t mounted if the output is empty

if the card is mounted unmount all partitions of it
```
umount /dev/mmcblk1p1
```
format the partition you want to use for Android data ⚠️ all data will be lost ⚠️
```
mkfs.btrfs /dev/mmcblk1p1
```
mount sd-card:
```
mount-sd.sh add mmcblk1p1
```
- the partition will be mounted on /media/sdcard/<UUID_of_partition>
stop all Android apps
stop Android layer
```
systemctl stop aliendalvik
```

copy existing data of apps

rsync -a --progress /data/media/ /media/sdcard/"$(blkid -o value -s UUID /dev/mmcblk1p1)"/android_storage/

correct the permissions

chown -R media_rw: /media/sdcard/"$(blkid -o value -s UUID /dev/mmcblk1p1)"/android_storage/
chmod -R 770 /media/sdcard/"$(blkid -o value -s UUID /dev/mmcblk1p1)"/android_storage/

create systemd-service file

echo "[Unit]
Description=Mount sd for android
After=mount-sd@mmcblk1p1.service

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/usr/local/sbin/mount-sd4android.sh start
ExecStop=/usr/local/sbin/mount-sd4android.sh stop

[Install]
WantedBy=graphical.target display.service" > /etc/systemd/system/mount-sd4android.service

create helper script

echo '#!/bin/bash

sd_uuid="$(blkid -o value -s UUID /dev/mmcblk1p1)"

if [ "$1" == "start" ]
then
    systemctl stop aliendalvik
    mount -o bind /media/sdcard/"${sd_uuid}"/android_storage /data/media
    systemctl start aliendalvik
elif [ "$1" == "stop" ]
then
    systemctl stop aliendalvik
    umount /data/media
fi' > /usr/local/sbin/mount-sd4android.sh

change permission of helper script

chmod ug+x /usr/local/sbin/mount-sd4android.sh

enable systemd-service

systemctl enable mount-sd4android.service

reboot your phone reboot
start terminal

check if all went well df -hT

all is ok if the output looks like:

/dev/mmcblk1p1
            btrfs     30G  8.4G   21G  29% /media/sdcard/4f1f8dbc-ed55-4b6c-8290-ac97e15b221f /dev/mmcblk1p1
            btrfs     30G  8.4G   21G  29% /data/media
/dev/fuse     fuse     30G  8.4G   21G  29% /home/nemo/android_storage

if all went well delete the old data

devel-su
mount-sd4android.sh stop
rm -rf /data/media/*
mount-sd4android.sh start