Where are the first executed bytes of a bootable cd?

Question

I took a look into the iso images (ISO 9660) of small Linux distributions. I found 16 empty sectors, followed by a sector describing the Primary Volume Description. Next sector is commonly a Boot Record containing only descriptive information such as System and Version Identifier and a little endian integer inside the unspecified byterange. Then comes the Supplementary Volume Descriptor and finally the Volume Descriptor Set Terminator.

I only guess it's a little endian integer in the Boot Record. I found no more Information about this. In all the images I used was the little endian integer smaller than the value for Sector Count from the Primary Volume Descriptor, so I further guess it's pointing to a sector inside the Image. Could someone provide more detailed informations about this?

Answer 1

The "El Torito Bootable CD-ROM Format Specification" describes the format of bootable CDs.