BIOS dump for the HP x360 13-ar0000au, built on Wistron board 18740-1, packed as a 7.37 MB RAR archive. Wistron board numbers use five digits followed by a dash revision, so confirm 18740-1 on the PCB before flashing. The name does not say whether the image is tested. Read and save the original SPI chip with a programmer first, since it holds serial and product information, and compare the dump length with the chip capacity to make sure the image fits.
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 @biosarchive. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →