23.12.2015 17:12, John Frankish пишет: >>>>> ..there is no error message, uefi boot works fine, but legacy bios >>>>> boot fails with an "invalid partition table" error >>>>> >>>> Where this error comes from? I do not see this string in GRUB sources >>>> and it really does not care; it would stop in rescue mode then >>>> >>> I guess the error message comes from the machine's bios - the legacy boot >>> doesn't get as far as starting grub. >>> >>>> Recently someone reported problem with booting rescue image on legacy >>>> BIOS >>>> - it would refuse to consider medium bootable unless medium has >>>> *msdos* partition table with active partition. This sounds like it could >>>> be the reason. >>>> >>> I'm not sure I understand - I thought the "EF02 BIOS boot partition" >>> achieved this aim? >>> >> >> BIOS boot is still GPT partition. >> >>> If not, what would the gpt partition table above look like including an >>> *msdos* partition table with active partition? >>> >> >> You can start with creating standard MSDOS partition table. >> >> EFI should be able to boot from it as well; and there is MSDOS partition >> type reserved for ESP (0xef). >> Install grub in MBR. If booting still fails, try to mark second partition >> bootable. >> > Thanks, this works: > > $ sudo fdisk /dev/sdc > ... > Device Boot Start End Blocks Id System > /dev/sdc1 * 2 128 1020127+ ef EFI (FAT-12/16/32)
Could you do me a favor and test if it also still works without any active partition? > /dev/sdc2 129 3797 29471242+ 83 Linux > ... > $ sudo x86_64-grub-install --target=x86_64-efi > --boot-directory=/mnt/sdc1/EFI/BOOT --efi-directory=/mnt/sdc1 --removable > Installation finished. No error reported. > > $ sudo x86_64-grub-install --target=i386-pc > --boot-directory=/mnt/sdc1/EFI/BOOT /dev/sdc > Installation finished. No error reported. > Hmm ... are sizes above in cylinders? > ..and both legacy-bios and uefi boot work. > There are reports that some EFI systems need GPT ... but I would suggest to leave it until you actually hit such system. > I still don't see why this doesn't work on gpt formatted media, but fine.. > That's the question to your BIOS vendor :) Apparently it tries to be too smart and "protect" you against errors. > ...and now (eventually) for the legacy-bios/uefi boot cd/iso ;) > If you aim at pure CD (not hybrid CD/HDD image) that is the most easy part :) _______________________________________________ Help-grub mailing list [email protected] https://lists.gnu.org/mailman/listinfo/help-grub
