Casper C300 file set for the D15R mainboard, revision 2.0; although catalogued as a boardview, the name says it holds main BIOS and EC firmware. Expect two images, one for the system SPI flash and one for the embedded controller, which governs power-on and charging. Extract the 3.20 MB 7z and inspect the contents before use. Confirm the PCB shows D15R rev 2.0, back up each chip first, and match every image to the size of the chip it belongs to before programming.
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 @biosfiles. Enginerys does not host this file.
How to open a .7z file
High-ratio compressed archive, often used for large BIOS collections.
7-ZipWinRARKeka (macOS)