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+# Steps to flash microG LineageOS on Samsung Galaxy S4
+
+download latest TWRP image from https://eu.dl.twrp.me/jflte/
+
+download latest lineageOS from https://download.lineage.microg.org/jfltexx/
+
+download latest su (arm) for 16.0 from https://download.lineageos.org/extras
+
+## Unlock the Bootloader / OEM
+
+Attach phone to PC. Use a good micro USB cable; make sure that you can use it
+to copy data.
+
+enable developer options
+
+enable USB debugging in developer options
+
+allow USB debugging access for your PC
+
+## Format Data for Encryption
+
+download official lineage recovery: https://download.lineageos.org/jfltexx
+
+`adb reboot bootloader`
+
+`heimdall flash --RECOVERY lineage-16.0-xxxxxxxx-recovery-jfltexx.img`
+
+It boots the system. But we want into the new recovery: `adb reboot recovery`.
+Now we need to take the following steps to format the data partition for
+LineageOS:
+
+- Factory Reset -> Wipe data / factory reset
+- Factory Reset -> Wipe System
+
+## Flash LineageOS
+
+Now go back into the recovery main menu, tap on "Apply Update", then "Apply
+from ADB". Then execute `adb sideload lineage-xxx.zip` on your PC.
+
+After a while, it warns you you that the signature verification failed, and
+whether you want to continue with the installation; answer "Yes".
+
+In the end, tap reboot to boot into the fresh LineageOS system.
+
+### Finish Installation
+
+Reboot to start LineageOS! 
+* When it says "No OS installed", you can ignore that, just swipe to the right.
+* When it asks you to install the TWRP app, you can safely click "Do not install".
+
+Go through the setup screen and choose what you want. You can be as restrictive
+as you want. Make sure to choose a Wi-Fi, so you can proceed with the next
+steps; you can also do this at any later time. 
+
+You should also choose a screen lock pin. Patterns are not very secure (you can
+often see them by holding the phone into the light at the right angle).
+Passwords are a bin inconvenient (but most secure). Do *not* use a fingerprint
+sensor, they are really insecure.
+
+## Device Encryption
+
+Charge the phone to 100%.
+
+Go to the Security Settings and encrypt the phone. During the process, it
+reboots once and asks you for the device PIN. It can take a while, but not soo
+long actually.
+
+## Flash TWRP
+
+*(You don't need TWRP, unless you want backup/restore functionality or so.)*
+
+`adb reboot bootloader`
+
+wait until bootloader mode is active: it says "Downloading... Do not turn off
+target !!"
+
+`heimdall flash --RECOVERY twrp-3.3.1-1-jflte.img`
+
+### Root Phone With addonsu
+
+*(You can also flash Magisk with the LineageOS recovery.)*
+
+Boot into your recovery, e.g. TWRP, with `adb reboot recovery`.
+
+Then go back, again to ADB Sideload, swipe to the right, and this time install
+Magisk with `adb sideload addonsu-16.0-arm-signed.zip`
+* When it shows `Total xfer: 1.77x` on the PC, and `script succeeded: result
+  was [1.000000]` in TWRP, it has suceeded.
+
+### Secure the device encryption
+
+You usually want to have a long password for your device encryption, which you
+only have to enter when the phone boots, and a shorter PIN for your lockscreen.
+By design, Android doesn't allow this; this is a workaround to make it possible
+still.
+
+We will also install an app which shuts down the phone when you get the unlock
+code wrong 5 times in a row.
+
+#### Wrong PIN Shutdown
+
+Open the F-Droid app, wait until it is done with "Updating repositories".
+
+Install the app "Wrong PIN Shutdown".
+
+Open "Wrong PIN Shutdown", grant Admin rights until forever, activate the
+function, and set it to shut down the phone after 5 wrong tries to enter the
+PIN. You can try it out directly - if you enter your PIN wrong 5 times, does it
+shut down? 
+
+#### Change the encryption password to a long password
+
+Then go to the Security settings and set the PIN you want to use for your
+lockscreen.
+
+Now you have to backup the files where it is saved. To do so, execute these
+commands with adb - you need to be connected to a PC with a proper USB cable:
+
+```
+adb root
+adb pull /data/system_de/0/spblob/
+adb pull /data/misc/keystore/user_0/1000_USRPKEY_synthetic_password_1bfba4c883309f16
+adb pull /data/system/locksettings.db
+```
+
+Now, go to the Security settings again, and change your PIN to the password you
+want to use for the encryption.
+
+Finally, you use adb again to restore the backup of the PIN, which changes your
+lockscreen PIN, but not your encryption passphrase:
+
+```
+adb push locksettings.db /data/system/locksettings.db
+adb push 1000_USRPKEY_synthetic_password_1bfba4c883309f16 /data/misc/keystore/user_0/1000_USRPKEY_synthetic_password_1bfba4c883309f16
+adb push spblob/ /data/system_de/0/
+```
+
+When you try to unlock your screen now, you will realize that you still have to
+enter the encryption passphrase. So reboot the phone; enter the encryption
+passphrase at startup, as desired. When the phone has booted, you can use the
+(shorter) PIN to unlock your phone.
+
+