Zipped firmware set tagged for Apple, named tbtrom, which suggests Thunderbolt controller ROM images, though the name lists no Mac model or board number. Thunderbolt controllers in Macs keep their firmware on a small separate SPI flash, and a damaged image can cause port or boot problems. Identify the logic board number and match it to the right image inside the archive before programming. Always read and save the existing chip first, and check that the image size matches the flash chip 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 @efibios. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →