Hi,
> that is what Thomas meant with hybrid ISO having both, good old MBR > BIOS and EFI support. That's modern extra hybrid: {PC-BIOS, EFI} x {DVD, USB-stick} The older ISO hybrid concept is {PC-BIOS} x {DVD, USB-stick} For the old hybrid, T2 uses a GRUB x86 El Torito Image and a GRUB MBR which is specialized on executing the El Torito Image as x86 program. This boot equipment can be seen in t2-minimal-glibc-gcc-i586-r48710.iso The El Torito image is accessible in the ISO as /boot/grub/i386-pc/eltorito.img The newer extra hybrids additionally have an EFI System Partition image as file (Fedora, Debian amd64, ...) or as nameless appended data blob (Knoppix 8.2+). This image is a FAT filesystem with the UEFI prescribed start programs and some GRUB menu (Knoppix uses SYSLINUX which does not work from DVD). The image gets advertised in the ISO as El Torito image for EFI and as partition of MBR type EF or of GPT Type GUID C12A7328-F81F-11D2-BA4B-00A0C93EC93B. As said, UEFI prescribes these partition IDs for hard-disk-like devices and El Torito for optical media. Many EFI implementations look at more places for the /EFI/BOOT/BOOT*.EFI programs. Microsoft Inc. obviously expects that all FAT filesystems get inspected which have a Microsoft MBR partition type for data. E.g. 0C or 0E. There are howtos which rely on this. No firmware implementer will dare to insist in a narrow interpretattion of UEFI specs. The fact that an inofficial location of the EFI programs works on one firmware does not indicate that it would work on the next firmware. So it is better to obey the specs veven if they are fewly enforced. Have a nice day :) Thomas ----------------------------------------------------------- If you wish to unsubscribe from this mailing, send mail to li...@t2-project.org with a subject of: unsubscribe t2