Installing custom firmware involves risks, including bricking your device or voiding your warranty. OPPO Global Community Requirements for Custom Firmware Unlocked Bootloader: This is the first step to allowing custom software. Custom Recovery: You must install a tool like TWRP (Team Win Recovery Project) to flash new files. Firmware File:

The most stable way to get Android 7.1.2 on an OPPO F1s (A1601) is through community-developed projects.

Before chasing custom ROMs, check if your device already has an official update that might suffice. OPPO’s last official firmware for the F1s was with ColorOS 3.2, build version A1601EX_11_A.30_181016 .

If you decide Android 7.1.2 is not for you, reverting is straightforward: