If your Huawei S7-721u is stuck in a bootloop, won't turn on, or is soft-bricked, you will need to use Windows-based flashing tools. This process is more complex and carries higher risks.
Due to the aging hardware (Qualcomm MSM7227, 512MB RAM), stock Android 2.3 is actually the most stable. However, enthusiasts have ported:
This article serves as a deep dive into the firmware ecosystem of the Huawei S7-721u, guiding you through the processes of upgrading, flashing, and the risks involved in modifying this legacy hardware.