Hi, Andrei Borzenkov wrote: > a) are we sure every EFI system out there accepts MBR (Apple?)
At least my favorite layout (see my recent mail 9837584093514267...@scdbackup.webframe.org) is explicitely promised by UEFI 2.4, "5.2.1 Legacy Master Boot Record (MBR)". The Apple problems in the blog of mjg, who invented the ISOLINUX+GRUB2 layout as of Fedora or Debian amd64, seemed rather related to the need for HFS(+). The Macs made him use MBR partition type 0x00, IIRC. http://mjg59.dreamwidth.org/11285.html (and older ones from within his endeavor) Since Vladimir provided HFS+ for libisofs, he might have some Apple knowledge in reserve. > b) GPT has nice feature of self-identifying block size. How this ? There are no block size fields in the GPT storage format. UEFI 2.4, 5.3.1 frightens me by "The device may present a logical block size that is not 512 bytes long." which would not play well with our habit to create image files which only later get onto some device. i wrote: > > Nevertheless, your overlapping layout would have the appeal of > > giving a mountable partition: > > [...] > > It would travel on the ticket that EFI shall ignore MBR partition > > type 0x00. > I'm not sure where this assumptions comes from. EFI does not say > anything about other partition types, UEFI 2.4, 5.2.1 Legacy Master Boot Record (MBR) "A Partition Record that contains an OSType value of zero or a SizeInLBA value of zero may be ignored." Table 14 shows OSType as byte at offset 4 in the MBR partition entry. Aka "partition type". The question is how far this ignoring goes. ishoybrid+GRUB2 as of mjg hopes for effective non-existence as far as EFI and its do-not-overlap demand is concerned. Have a nice day :) Thomas _______________________________________________ Bug-grub mailing list Bug-grub@gnu.org https://lists.gnu.org/mailman/listinfo/bug-grub