The primary function of these tools is to interface with the device's diagnostic (DIAG) port to read and write the NV (Non-Volatile) RAM data, which contains the device's unique identifier and radio frequency (RF) parameters.
This is where the enters the picture. A standard user cannot manually rewrite the hexadecimal values in NVRAM. The tool is designed to scan the phone’s file system, locate the corrupted or missing IMEI data, and either: qualcomm imei rebuilder tool