Oppo A9 Custom Rom (2024)

Abstract The Oppo A9 (2019) occupies a strange purgatory in smartphone history. Shipped with Android 9 (ColorOS 6) and receiving only a lackluster update to Android 11 (ColorOS 11), it was abandoned long before its hardware gave out. Unlike its Snapdragon-powered cousins, the A9 features a MediaTek Helio P35 —a chipset notorious in the modding community for locked bootloaders and a dearth of source code. This paper explores the underground war to bring Custom ROMs (like GSI and Treble) to the Oppo A9, examining why users risk bricking their devices for a few extra years of life. 1. The Paradox of the "Dead" Chipset Most custom ROM communities thrive on Qualcomm chips due to readily available kernel sources. The Oppo A9’s MT6765 is a different beast. Officially, MediaTek is the enemy of the "tinkerer." However, Project Treble (introduced in Android 8) created a loophole. The Oppo A9 shipped with Treble support, meaning the vendor implementation (VNDK) is separated from the Android framework.