Replaces critical partitions, including System , Boot , and Recovery , and may also update the radio image.
In the early era of Android smartphones, Over-The-Air (OTA) updates were often unreliable, slow, or carrier-restricted. To ensure devices could be updated or restored to factory settings, manufacturers relied on PC-tethered flashing tools. For HTC devices—such as the HTC Dream (T-Mobile G1), HTC Hero, and the iconic HTC Evo—the standard tool was the ROM Update Utility (RUU). htc android phone rom update utility