Thomas Schmitt, 2012-02-02 12:52+0100: > > For optical media, I am not really sure: it may use ElTorito or load a > > file /efi/boot/boot<arch>.efi from the ISO-9660 or UDF filesystem, so > > this should be checked. > > GRUB2 grub-mkrescue can produce (U)EFI bootable ISO 9660 images, where > booting shall start at the El Torito Boot Record. (I only provide the > ISO image generator, so i have no insight what happens at boot time.) All right, I was not sure of how optical media were supposed to be handled since the UEFI specification is not very clear about them. Regular El Torito then. > > It would be possible to create hybrid BIOS/UEFI bootable images, but > > that will probably be incompatible with hybrid USB/optical images as we > > have them currently. > > Where would be the incompatibility with isohybrid ISOLINUX in particular ? > If it is only lack of necessary UEFI support in SYSLINUX/ISOLINUX, then > one could consider grub-mkrescue as base for optical media and USB sticks. UEFI booting requires a GPT and a special partition, which would probably be impossible to implement along with the MBR hack for hybrid booting. > It produces an MBR and El Torito boot equipment, which can point to > boot loaders for PC-BIOS and to boot loaders for (U)EFI at the same time. > It already uses xorriso as ISO generator. So Jigdo production would be > no big problem. > > The MBR marks the ISO image and could mark a further FAT partition. > I would also propose my pet feature, 32 kB offset of partition 1. Well, perhaps that could work after all. But it would have to be a GPT, not only an MBR. > > An EFI System Partition is basically a regular partition, > > Recognized at boot time from MBR ? (Or from where else ?) Recognized by the UEFI boot manager, as a GPT partition with the correct type. -- Tanguy Ortolo
Attachment:
signature.asc
Description: Digital signature