fastboot flash system system.img
Custom ROM for Vivo Y1s — Guide, Recommended ROMs, and Installation Steps vivo y1s custom rom
If you only want a faster phone without the risk of bricking: fastboot flash system system
After booting into your new custom ROM, you might encounter issues: vivo y1s custom rom
For purists who want the absolute barebones version of Android without any extra features or bloat.
Since the Vivo Y1s launched with Android 10, it supports Project Treble . This means users can technically flash GSIs (Generic System Images). However, this requires a workaround to unlock the bootloader, which often involves paid authorized accounts or specific MediaTek exploit tools (like MTK Client).