ROM Installation Guide

Note

Before following this guide, make sure you’ve unlocked bootloader and installed an appropriate recovery. Check this guide on how to do so.

Types of Flashing

Installing a ROM is often called ‘flashing’ a ROM. There are two types of flashing:

1. Clean flash, and
2. Dirty flash.

The difference between a clean flash and a dirty flash is that clean flash wipes your data, and a dirty flash retains your data.

You must do a clean flash when flashing a ROM that differs from your current ROM. For example, switching from LineageOS to PixelOS requires a clean flash. Make sure to back up your data.

Dirty flash can be performed when upgrading to the same ROM, unless the ROM maintainer explicitly tells you to do a clean flash.

Caution

For both clean flash and dirty flash, if you are flashing ROMs where the RUI firmware version differ than the one currently installed, make sure to flash the right recovery before the last step (which is reboot). See this to learn more.

Performing a Clean Flash

1. Reboot to recovery.
2. Wipe dalvik cache, cache and data.
3. Flash the ROM (and GAPPS if necessary).
4. Change filesystem type of userdata/data to f2fs. This will automatically perform a format. See Caveat section on to why you should just use f2fs instead of ext4.
5. Reboot to system and you’re done.

Performing a Dirty Flash

1. Reboot to recovery.
2. Flash the ROM (and GAPPS if necessary).
3. Wipe cache and dalvik cache. DO NOT wipe data.
4. Reboot to system.

Caveat

In Android 16, f2fs is mandatory. You cannot dirty flash Android 16, even for the same ROM if you were previously using ext4, as converting filesystem to f2fs will perform a format of your data.

Even in Android 15 and below, there’s not much point in using ext4 as f2fs boasts a better storage performance.