today i taught a CTO of a computer company about "El Torito" (the Bootable CD-ROM Format Specification)
it took me way too long to find this so i'm posting it here before i forget it
- if the disk has a GUID Partition Table (GPT), any partition with the EFI system partition type GUID
C12A7328-F81F-11D2-BA4B-00A0C93EC93B - if the disk is an ISO 9660 filesystem, an El Torito Boot Catalog entry with platform ID 0xEF (which is expected to point at sectors containing a FAT filesystem like any other EFI system partition, as opposed to the otherwise-expected boot code)
- if the disk has an MBR (but no GPT), any partition with the partition type 0xEF, including nested MBRs within partitions (presumably to deal with extended partitions, but why not specify that?!?! are you really doing depth-first search??)
i am going to make a disk image that finds an EFI system partition when copied to a device with 4k sectors, El Torito on 2k sectors, and a 128-times nested MBR on 512-byte sectors
