Chroot on Android
Content
- Good to Mention
- Choosing a rootfs
- Extracting the rootfs
- Making a script to launch the chroot environment
- Troubleshooting
- Fixing apt under debian based ditros
- Fixing network issues
Good to Mention
- You need a rooted phone for that
- I’ve used here a Samsung S10+ phone running Lineage OS 19.1
- If any damage happens to your phone, you are all responsible for it!
Choosing a rootfs
the rootfs architecture have to match with your device architecture too, to know what architecture your phone have run:
$ uname -maarch64
(e.g. aarch64, armv7l).
Extracting the rootfs
Any location under /data should be good (because it formatted as ext4)
e.g.
$ mkdir chroot #or anything else
$ sudo tar xfp /sdcard/Download/rootfs.tar.xz -C /data/ubuntu #to keep the files permissions
Making a script to launch the chroot environment
Use nano or any text editor you like for that:
$ nano run-chroot.sh
simple example:
#!/bin/sh# fix /dev mount options
mount -o remount,dev,suid /datamount --bind /dev /data/ubuntu/dev
mount --bind /sys /data/ubuntu/sys
mount --bind /proc /data/ubuntu/proc
mount --bind /dev/pts /data/ubuntu/dev/ptsexport PATH=/bin:/sbin:/usr/bin:/usr/sbin
export TERM=$TERM
export TMPDIR=/tmpchroot /data/ubuntu/ /bin/su - root
then change the file permissions to executable:
$ chmod +x run-chroot.sh
you have to run it as root:
$ sudo ./run-chroot.sh
Troubleshooting
Fixing apt under debian based ditros
usermod -g 3003 _apt
Fixing network issues
you have to add a DNS to resolv.conf:
echo "nameserver 8.8.8.8" > /etc/resolv.conf
then you need to add android root groups:
groupadd -g 3001 aid_bt
groupadd -g 3002 aid_bt_net
groupadd -g 3003 aid_inet
groupadd -g 3004 aid_net_raw
groupadd -g 3005 aid_admin
then add those groups to the user you using:
usermod -a -G aid_bt,aid_bt_net,aid_inet,aid_net_raw,aid_admin root
