Finding a specific "flash dump" for a HiSilicon-based DVR like the HI3521A V123 1080N16

typically requires accessing specialized firmware repositories or manufacturer support pages, as these files are unique to the hardware's flash chip. Where to Find Firmware and Flash Dumps

: Place the extracted firmware files (often named rootfs-3521a ) directly in the root directory of the USB drive, not inside any folders.

: Many DVR brands using the HI3521A chipset provide firmware updates. For example, Zosi Support offers upgrade files for models using the Hi3521A chip.