You can try to replace the actual microcode-sections in the bios-file manually using hex-editor. Only working with uncompressed/unencrypted files.
thanks for your efforts, perhaps it would work if the FFS checksum of the raw file volume was correct, is there a way to do it manually?
The CRC was just to confirm if the file wasn't corrupted, since you uploaded the BIOS file without compression (zip/rar). Anyway, I just flashed it and Windows is now able to boot and the cpu is correctly identified! Thanks once again!