===== ESF menu file type =====

<code>
    0..3    ESFf
    4..5    Version major
    6..7    Version minor
    8..25   Unknown
    26      Compression flag (1-uncompressed 2-compressed)
    27..35  Unknown
</code>

The rest of the file is compressed by the same compression as a [[rootfs|cramfs image]] and use the same method from kernel.