Main BIOS archive for the Lenovo IdeaPad S400, 3.74 MB in RAR form. The word main suggests the system BIOS rather than EC firmware, but the name gives no board number or version. The S400 exists on more than one Compal board, so check the motherboard label before use. Write the image to the SPI chip with a programmer only after reading and saving the original, and check that the image size fits the flash chip's capacity.
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 →