Despite being filed as firmware, the name describes a schematic diagram for the Xiaomi Redmi Note 9 Pro, supplied as a ZIP of roughly 1.90 MB. Expect circuit pages rather than a flashable image. A schematic of this kind is used to trace PMIC outputs, battery and charging lines, display and camera interfaces and to identify components around a failed circuit. Open the extracted files in a PDF viewer, and since the Redmi Note 9 Pro shares hardware with sibling models, confirm the board version matches.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @mischematic. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →