The Android custom ROM scene has reached another milestone. The Xiaomi Mi A1 (codename tissot)—first launched in September 2017—has officially booted Android 17, this time running on the feature-rich Evolution X custom ROM.
The Device That Refuses to Retire
When Xiaomi introduced the Mi A1 under Google’s Android One program, it arrived running Android 7.1.2 Nougat. Official vendor support concluded after Android 9 Pie. Nearly a decade later, the device’s Qualcomm Snapdragon 625 (MSM8953) platform continues to outlive expectations.
What makes this release especially symbolic is the connection between the device and the firmware:
- Evolution X’s Roots: The Mi A1 (
tissot) was the first device officially supported when Evolution X was founded in March 2019. - Full-Circle Support: Seeing the team bring Android 17 to the exact device where the ROM began highlights the persistence of open-source maintenance.
Technical Feats on Decade-Old Silicon
Porting a modern Android source tree packed with Evolution X’s extensive customization engine (“The Evolver”) and Pixel styling onto a 14nm SoC with 4 GB LPDDR3 RAM requires major low-level rework:
- Storage Repartitioning: The factory partition layout on
tissotwas never designed for multi-gigabyte modern system and product images. Custom repartition scripts reallocate legacy cache and reserve space to fit the current system trees. - AIDL & Binder Shims: Bridging legacy hardware abstraction layers (HALs) and proprietary vendor blobs from the Linux 3.18/4.9 kernel era to modern Android AIDL interfaces requires custom shims, particularly for the radio interface layer (RIL), sensors, and camera stacks.
- RAM Optimization: Running full Pixel system UI components and customizations inside 4 GB of RAM calls for aggressive ZRAM compression, tuned swappiness, and optimized low-memory killer (LMK) thresholds to prevent constant launcher redraws.
The build confirms once again that as long as kernel sources and dedicated developers exist, legacy hardware can continue running long after official support windows close.
