1. Executive Summary The Samsung Galaxy A40 (codenamed a40 ) was released in 2019 with Android 9 (Pie). While Samsung has ended official OS updates (last being Android 11/OneUI 3.1), the device maintains an active community on XDA Forums . Due to its Exynos 7904 SoC, development is more complex than Qualcomm devices, but several stable, maintained custom ROMs exist, extending the device's life to Android 13 and 14. 2. Device Prerequisites (Critical) Before installing any custom ROM, the following must be completed:

| Requirement | Status on A40 | Notes | |-------------|---------------|-------| | | Required | Enables "OEM Unlocking" in Developer Options. Warning: Trips Knox (warranty void, Samsung Pay/Pass permanently broken). | | TWRP (Custom Recovery) | Available (v3.7.0+) | Mandatory for flashing ROMs. Unofficial but stable builds exist. | | VBETA Disabling | Required | Samsung's Verified Boot must be disabled via patched vbmeta.img . | | Backup EFS/IMEI | Critical | Exynos devices risk losing IMEI. Backup via TWRP is mandatory. | 3. Available Custom ROMs (Active as of 2025) The following ROMs are confirmed stable for daily use on the A40: