For my Galaxy Nexus (maguro) with Android 4.4, I installed LineageOS when Google stopped supporting the device. Unfortunately I forgot the install procedure. It landed with Android 6.
With the Android Developer Tools
including adb and the appropriate
/etc/udev/rules.d to recognize the phone,
I installed the app store
F-droid for Android 6.
However somewhere after 2022 this ceased to work
presumably because of certificates.
Fortunately
stoutner
knew how to install the
isrgrootx1.pem
[src]
root certificate from
Lets Encrypt
which F-droid uses.
mv isrgrootx1.pem.txt isrgrootx1.pem adb push isrgrootx1.pem /sdcard
Then on the phone, Security→Install Certificates from Storage choose file with name "letsencrypt2026", usage "vpn and apps". For some reason, you will be forced to select a PIN.
Now updating and installing should work again on F-droid. Install
SimpleSSHD
and get your .ssh/authorized_keys from
~/.ssh/id_rsa.pub ready.
adb push authorized_keys /storage/emulated/0/Podcasts
On the phone in SimpleSSHD, select Settings→SSH Path
and Home Directory
to /storage/emulated/0/Podcasts
and change port number from 2222
to something you like. Or not.
Note that /sdcard is a symlink to /storage/emulated/0.
Upon start, SimpleSSHD will show you which IP it operates on.
So on the notebook:
ssh -p 2222 192.168.100.68 scp -P 2222 myvoice.mp3 192.168.100.68:/sdcard/Music
... and you can get access to the phone filesystem without
adb from now on.
Suppose you want to restrict access to e.g. the camera app. Settings→Privacy→Protected Apps (Datenschutz→Geschützte Apps) presents you an app list with checkboxes which allow you to hide apps from the menu and also forbid calling by Intent, with e.g. a pattern as password. I usually do this e.g. to the camera so the phone will not be awash with random fotos.
To reactivate an app, you can either uncheck the checkbox again or in Settings→Apps choose an app, then click the gray lock symbol in the upper right corner, which requests the password pattern for unlocking. Unfortunately there is no way to re-lock from here.
EOF (Feb:2026)