Firmware archive labelled for a Kurshio BL-521DLD-LF, 545 KB in RAR format. The name carries only that model string and no version, chip or revision details, so the contents need to be checked before use. Small dumps like this are usually written to an SPI or EEPROM memory with a programmer to revive a device whose firmware is corrupted. Identify the memory chip on your board, compare its capacity with the extracted file size, and read out and keep the original contents before overwriting them.
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 →