Search for ZLT-P21-firmware. Legit developers post OpenWRT builds here. Example repository structure includes an update.bin and a factory.bin.
The enthusiast community (primarily via 4pda and GitHub) has reverse-engineered the P21’s Qualcomm MDM9230 chipset. "Better" firmware—custom builds based on modified stock images or OpenWRT derivatives—delivers four transformative features. zlt p21 firmware better
When users search for "better firmware," they aren't looking for cosmetic changes. They want tangible, measurable improvements. A superior firmware build for the ZLT P21 delivers: Search for ZLT-P21-firmware