On 06/20/2017 12:47 PM, Laszlo Ersek wrote: > On 06/20/17 14:34, Heyi Guo wrote: > >> Several tools like mount in Linux will show all files together >> including EFI/BOOT directory, > > That directory, displayed as part of the ISO9660 filesystem that was > written to the ISO image / CD-ROM, is entirely irrelevant when it comes > to UEFI-bootability. I doesn't even need to exist, and if it does, it's > likely there only for convenience reasons (so that people don't have to > run "dumpet" or similar tools to extract the FAT image first, and then > the EFI binaries second, if they want to investigate the EFI binaries). > > For UEFI boot, only the ElTorito image matters.
MOSTLY, yes; however, some EFI implementations include ISO-9660 drivers. This is definitely true of the EFI used by VirtualBox. I think I've seen this feature on one or two UEFI-based PCs, too, but I don't recall the details and I can't say I'm 100% certain of this. There are also ISO-9660 drivers floating around that can be loaded from a FAT partition. In either of these cases, the files on the ISO-9660 filesystem can be used to boot from an optical disc, even if it lacks the El Torito image. This is admittedly a corner case at best; but IMHO it's worth keeping in mind, since non-matching El Torito and ISO-9660 files could lead to user (or developer) confusion. -- Rod Smith [email protected] http://www.rodsbooks.com _______________________________________________ edk2-devel mailing list [email protected] https://lists.01.org/mailman/listinfo/edk2-devel
