RAR archive of 2.91 MB with firmware for the W540 laptop, board LKM-1, Wistron number 12291-2, marked SP11. The SP11 tag is not explained in the name and presumably separates it from the SP12 version, so compare both before choosing. Technicians use such dumps to rewrite a damaged BIOS chip with an SPI programmer. Wistron uses the 12291 style board numbering, so confirm your board carries 12291-2, save the original flash contents first and make sure the image matches the chip size.
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 @SCHEMATICWORLD. 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.